diff --git a/src/main/java/org/redisson/RedissonScoredSortedSet.java b/src/main/java/org/redisson/RedissonScoredSortedSet.java
index bba0dfd73..8c51b17b5 100644
--- a/src/main/java/org/redisson/RedissonScoredSortedSet.java
+++ b/src/main/java/org/redisson/RedissonScoredSortedSet.java
@@ -26,9 +26,9 @@ import org.redisson.client.RedisClient;
 import org.redisson.client.codec.StringCodec;
 import org.redisson.client.protocol.RedisCommand;
 import org.redisson.client.protocol.RedisCommands;
+import org.redisson.client.protocol.ScoredEntry;
 import org.redisson.client.protocol.convertor.BooleanReplayConvertor;
 import org.redisson.client.protocol.decoder.ListScanResult;
-import org.redisson.client.protocol.decoder.ScoredEntry;
 import org.redisson.core.RScoredSortedSet;
 
 import io.netty.util.concurrent.Future;
@@ -46,6 +46,10 @@ public class RedissonScoredSortedSet<V> extends RedissonExpirable implements RSc
 
     @Override
     public Future<Boolean> addAsync(double score, V object) {
+        // String should be encoded as String to let lex functions work properly
+        if (object instanceof String) {
+            return commandExecutor.writeAsync(getName(), StringCodec.INSTANCE, RedisCommands.ZADD, getName(), BigDecimal.valueOf(score).toPlainString(), object);
+        }
         return commandExecutor.writeAsync(getName(), RedisCommands.ZADD, getName(), BigDecimal.valueOf(score).toPlainString(), object);
     }
 
@@ -90,15 +94,25 @@ public class RedissonScoredSortedSet<V> extends RedissonExpirable implements RSc
     }
 
     @Override
-    public Double getScore(Object o) {
+    public Double getScore(V o) {
         return get(getScoreAsync(o));
     }
 
     @Override
-    public Future<Double> getScoreAsync(Object o) {
+    public Future<Double> getScoreAsync(V o) {
         return commandExecutor.readAsync(getName(), RedisCommands.ZSCORE, getName(), o);
     }
 
+    @Override
+    public Integer rank(V o) {
+        return get(rankAsync(o));
+    }
+
+    @Override
+    public Future<Integer> rankAsync(V o) {
+        return commandExecutor.readAsync(getName(), RedisCommands.ZRANK, getName(), o);
+    }
+
     private ListScanResult<V> scanIterator(RedisClient client, long startPos) {
         return commandExecutor.read(client, getName(), RedisCommands.ZSCAN, getName(), startPos);
     }
@@ -259,9 +273,32 @@ public class RedissonScoredSortedSet<V> extends RedissonExpirable implements RSc
     }
 
     @Override
-    public Future<Collection<ScoredEntry<V>>> entryRangeAsync(int startIndex,
-            int endIndex) {
+    public Future<Collection<ScoredEntry<V>>> entryRangeAsync(int startIndex, int endIndex) {
         return commandExecutor.readAsync(getName(), RedisCommands.ZRANGE_ENTRY, getName(), startIndex, endIndex, "WITHSCORES");
     }
 
+    @Override
+    public Integer lexCount(V fromElement, boolean fromInclusive, V toElement, boolean toInclusive) {
+        return get(lexCountAsync(fromElement, fromInclusive, toElement, toInclusive));
+    }
+
+    @Override
+    public Future<Integer> lexCountAsync(V fromElement, boolean fromInclusive, V toElement, boolean toInclusive) {
+        String fromValue = fromElement.toString();
+        if (fromInclusive) {
+            fromValue = "[" + fromValue;
+        } else {
+            fromValue = "(" + fromValue;
+        }
+
+        String toValue = toElement.toString();
+        if (toInclusive) {
+            toValue = "[" + toValue;
+        } else {
+            toValue = "(" + toValue;
+        }
+
+        return commandExecutor.readAsync(getName(), RedisCommands.ZLEXCOUNT, getName(), fromValue, toValue);
+    }
+
 }
diff --git a/src/main/java/org/redisson/client/protocol/RedisCommands.java b/src/main/java/org/redisson/client/protocol/RedisCommands.java
index a3f4e6c17..4d9000830 100644
--- a/src/main/java/org/redisson/client/protocol/RedisCommands.java
+++ b/src/main/java/org/redisson/client/protocol/RedisCommands.java
@@ -37,7 +37,6 @@ import org.redisson.client.protocol.decoder.NestedMultiDecoder;
 import org.redisson.client.protocol.decoder.ObjectListReplayDecoder;
 import org.redisson.client.protocol.decoder.ObjectMapReplayDecoder;
 import org.redisson.client.protocol.decoder.ObjectSetReplayDecoder;
-import org.redisson.client.protocol.decoder.ScoredEntry;
 import org.redisson.client.protocol.decoder.ScoredSortedSetReplayDecoder;
 import org.redisson.client.protocol.decoder.ScoredSortedSetScanReplayDecoder;
 import org.redisson.client.protocol.decoder.StringDataDecoder;
@@ -52,8 +51,10 @@ public interface RedisCommands {
     RedisCommand<Boolean> ZADD = new RedisCommand<Boolean>("ZADD", new BooleanAmountReplayConvertor(), 3);
     RedisCommand<Boolean> ZREM = new RedisCommand<Boolean>("ZREM", new BooleanAmountReplayConvertor(), 2);
     RedisStrictCommand<Integer> ZCARD = new RedisStrictCommand<Integer>("ZCARD", new IntegerReplayConvertor());
+    RedisStrictCommand<Integer> ZLEXCOUNT = new RedisStrictCommand<Integer>("ZLEXCOUNT", new IntegerReplayConvertor());
     RedisCommand<Boolean> ZSCORE_CONTAINS = new RedisCommand<Boolean>("ZSCORE", new BooleanNotNullReplayConvertor(), 2);
     RedisStrictCommand<Double> ZSCORE = new RedisStrictCommand<Double>("ZSCORE", new DoubleReplayConvertor());
+    RedisStrictCommand<Integer> ZRANK = new RedisStrictCommand<Integer>("ZRANK", new IntegerReplayConvertor());
     RedisCommand<List<Object>> ZRANGE = new RedisCommand<List<Object>>("ZRANGE", new ObjectListReplayDecoder<Object>());
     RedisCommand<List<ScoredEntry<Object>>> ZRANGE_ENTRY = new RedisCommand<List<ScoredEntry<Object>>>("ZRANGE", new ScoredSortedSetReplayDecoder<Object>());
     RedisCommand<ListScanResult<Object>> ZSCAN = new RedisCommand<ListScanResult<Object>>("ZSCAN", new NestedMultiDecoder(new ObjectListReplayDecoder<Object>(), new ScoredSortedSetScanReplayDecoder()), ValueType.OBJECT);
diff --git a/src/main/java/org/redisson/client/protocol/decoder/ScoredEntry.java b/src/main/java/org/redisson/client/protocol/ScoredEntry.java
similarity index 97%
rename from src/main/java/org/redisson/client/protocol/decoder/ScoredEntry.java
rename to src/main/java/org/redisson/client/protocol/ScoredEntry.java
index 398fc799b..9bbd56801 100644
--- a/src/main/java/org/redisson/client/protocol/decoder/ScoredEntry.java
+++ b/src/main/java/org/redisson/client/protocol/ScoredEntry.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.redisson.client.protocol.decoder;
+package org.redisson.client.protocol;
 
 public class ScoredEntry<V> {
 
diff --git a/src/main/java/org/redisson/client/protocol/decoder/ScoredSortedSetReplayDecoder.java b/src/main/java/org/redisson/client/protocol/decoder/ScoredSortedSetReplayDecoder.java
index bfa322082..5a77210ce 100644
--- a/src/main/java/org/redisson/client/protocol/decoder/ScoredSortedSetReplayDecoder.java
+++ b/src/main/java/org/redisson/client/protocol/decoder/ScoredSortedSetReplayDecoder.java
@@ -19,6 +19,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.redisson.client.handler.State;
+import org.redisson.client.protocol.ScoredEntry;
 
 import io.netty.buffer.ByteBuf;
 
diff --git a/src/main/java/org/redisson/core/RScoredSortedSet.java b/src/main/java/org/redisson/core/RScoredSortedSet.java
index 5d55e4902..12bb19aef 100644
--- a/src/main/java/org/redisson/core/RScoredSortedSet.java
+++ b/src/main/java/org/redisson/core/RScoredSortedSet.java
@@ -17,11 +17,15 @@ package org.redisson.core;
 
 import java.util.Collection;
 
-import org.redisson.client.protocol.decoder.ScoredEntry;
+import org.redisson.client.protocol.ScoredEntry;
 
 public interface RScoredSortedSet<V> extends RScoredSortedSetAsync<V>, Iterable<V>, RExpirable {
 
-    Double getScore(Object o);
+    Integer lexCount(V fromElement, boolean fromInclusive, V toElement, boolean toInclusive);
+
+    Integer rank(V o);
+
+    Double getScore(V o);
 
     boolean add(double score, V object);
 
diff --git a/src/main/java/org/redisson/core/RScoredSortedSetAsync.java b/src/main/java/org/redisson/core/RScoredSortedSetAsync.java
index ef89c3551..8802fa45f 100644
--- a/src/main/java/org/redisson/core/RScoredSortedSetAsync.java
+++ b/src/main/java/org/redisson/core/RScoredSortedSetAsync.java
@@ -17,13 +17,17 @@ package org.redisson.core;
 
 import java.util.Collection;
 
-import org.redisson.client.protocol.decoder.ScoredEntry;
+import org.redisson.client.protocol.ScoredEntry;
 
 import io.netty.util.concurrent.Future;
 
 public interface RScoredSortedSetAsync<V> extends RExpirableAsync {
 
-    Future<Double> getScoreAsync(Object o);
+    Future<Integer> lexCountAsync(V fromElement, boolean fromInclusive, V toElement, boolean toInclusive);
+
+    Future<Integer> rankAsync(V o);
+
+    Future<Double> getScoreAsync(V o);
 
     Future<Boolean> addAsync(double score, V object);
 
diff --git a/src/test/java/org/redisson/RedissonScoredSortedSetTest.java b/src/test/java/org/redisson/RedissonScoredSortedSetTest.java
index 4af77772d..f64096ff5 100644
--- a/src/test/java/org/redisson/RedissonScoredSortedSetTest.java
+++ b/src/test/java/org/redisson/RedissonScoredSortedSetTest.java
@@ -1,10 +1,7 @@
 package org.redisson;
 
-import io.netty.util.concurrent.Future;
-
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
@@ -16,13 +13,43 @@ import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
 import org.junit.Assert;
 import org.junit.Test;
-import org.redisson.client.protocol.decoder.ScoredEntry;
-import org.redisson.core.RMap;
+import org.redisson.client.protocol.ScoredEntry;
 import org.redisson.core.RScoredSortedSet;
 import org.redisson.core.RSortedSet;
 
+import io.netty.util.concurrent.Future;
+
 public class RedissonScoredSortedSetTest extends BaseTest {
 
+    @Test
+    public void testRank() {
+        RScoredSortedSet<String> set = redisson.getScoredSortedSet("simple");
+        set.add(0.1, "a");
+        set.add(0.2, "b");
+        set.add(0.3, "c");
+        set.add(0.4, "d");
+        set.add(0.5, "e");
+        set.add(0.6, "f");
+        set.add(0.7, "g");
+
+        Assert.assertEquals(3, (int)set.rank("d"));
+    }
+
+    @Test
+    public void testLexCount() {
+        RScoredSortedSet<String> set = redisson.getScoredSortedSet("simple");
+        set.add(0, "a");
+        set.add(0, "b");
+        set.add(0, "c");
+        set.add(0, "d");
+        set.add(0, "e");
+        set.add(0, "f");
+        set.add(0, "g");
+
+        Assert.assertEquals(5, (int)set.lexCount("b", true, "f", true));
+        Assert.assertEquals(3, (int)set.lexCount("b", false, "f", false));
+    }
+
     @Test
     public void testAddAsync() throws InterruptedException, ExecutionException {
         RScoredSortedSet<Integer> set = redisson.getScoredSortedSet("simple");