diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionInfo.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionInfo.java
index 80b7c42561d..918f1463a51 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionInfo.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionInfo.java
@@ -148,6 +148,9 @@ public class HRegionInfo implements Comparable<HRegionInfo> {
 
   private static final int MAX_REPLICA_ID = 0xFFFF;
   public static final int DEFAULT_REPLICA_ID = 0;
+
+  public static final String INVALID_REGION_NAME_FORMAT_MESSAGE = "Invalid regionName format";
+
   /**
    * Does region name contain its encoded name?
    * @param regionName region name
@@ -575,7 +578,8 @@ public class HRegionInfo implements Comparable<HRegionInfo> {
       }
     }
     if (offset == -1) {
-      throw new IOException("Invalid regionName format: " + Bytes.toStringBinary(regionName));
+      throw new IOException(INVALID_REGION_NAME_FORMAT_MESSAGE
+        + ": " + Bytes.toStringBinary(regionName));
     }
     byte[] tableName = new byte[offset];
     System.arraycopy(regionName, 0, tableName, 0, offset);
@@ -606,7 +610,8 @@ public class HRegionInfo implements Comparable<HRegionInfo> {
       }
     }
     if (offset == -1) {
-      throw new IOException("Invalid regionName format: " + Bytes.toStringBinary(regionName));
+      throw new IOException(INVALID_REGION_NAME_FORMAT_MESSAGE
+        + ": " + Bytes.toStringBinary(regionName));
     }
     byte [] startKey = HConstants.EMPTY_BYTE_ARRAY;
     if(offset != tableName.length + 1) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java
index ae0ec35180a..b40f30e2c95 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java
@@ -768,13 +768,13 @@ public interface Admin extends Abortable, Closeable {
   /**
    * Merge two regions. Asynchronous operation.
    *
-   * @param encodedNameOfRegionA encoded name of region a
-   * @param encodedNameOfRegionB encoded name of region b
+   * @param nameOfRegionA encoded or full name of region a
+   * @param nameOfRegionB encoded or full name of region b
    * @param forcible true if do a compulsory merge, otherwise we will only merge two adjacent
    * regions
    * @throws IOException
    */
-  void mergeRegions(final byte[] encodedNameOfRegionA, final byte[] encodedNameOfRegionB,
+  void mergeRegions(final byte[] nameOfRegionA, final byte[] nameOfRegionB,
       final boolean forcible) throws IOException;
 
   /**
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
index 3b808440cf7..b2c7f51223a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
@@ -2434,22 +2434,40 @@ public class HBaseAdmin implements Admin {
     });
   }
 
+  private boolean isEncodedRegionName(byte[] regionName) throws IOException {
+    try {
+      HRegionInfo.parseRegionName(regionName);
+      return false;
+    } catch (IOException e) {
+      if (StringUtils.stringifyException(e)
+        .contains(HRegionInfo.INVALID_REGION_NAME_FORMAT_MESSAGE)) {
+        return true;
+      }
+      throw e;
+    }
+  }
+
   /**
    * Merge two regions. Asynchronous operation.
-   * @param encodedNameOfRegionA encoded name of region a
-   * @param encodedNameOfRegionB encoded name of region b
+   * @param nameOfRegionA encoded or full name of region a
+   * @param nameOfRegionB encoded or full name of region b
    * @param forcible true if do a compulsory merge, otherwise we will only merge
    *          two adjacent regions
    * @throws IOException
    */
   @Override
-  public void mergeRegions(final byte[] encodedNameOfRegionA,
-      final byte[] encodedNameOfRegionB, final boolean forcible)
+  public void mergeRegions(final byte[] nameOfRegionA,
+      final byte[] nameOfRegionB, final boolean forcible)
       throws IOException {
-    Pair<HRegionInfo, ServerName> pair = getRegion(encodedNameOfRegionA);
+    final byte[] encodedNameOfRegionA = isEncodedRegionName(nameOfRegionA) ?
+      nameOfRegionA : HRegionInfo.encodeRegionName(nameOfRegionA).getBytes();
+    final byte[] encodedNameOfRegionB = isEncodedRegionName(nameOfRegionB) ?
+      nameOfRegionB : HRegionInfo.encodeRegionName(nameOfRegionB).getBytes();
+
+    Pair<HRegionInfo, ServerName> pair = getRegion(nameOfRegionA);
     if (pair != null && pair.getFirst().getReplicaId() != HRegionInfo.DEFAULT_REPLICA_ID)
       throw new IllegalArgumentException("Can't invoke merge on non-default regions directly");
-    pair = getRegion(encodedNameOfRegionB);
+    pair = getRegion(nameOfRegionB);
     if (pair != null && pair.getFirst().getReplicaId() != HRegionInfo.DEFAULT_REPLICA_ID)
       throw new IllegalArgumentException("Can't invoke merge on non-default regions directly");
     executeCallable(new MasterCallable<Void>(getConnection()) {
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin1.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin1.java
index a3652200d1d..6b68b5ec50f 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin1.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin1.java
@@ -1407,4 +1407,43 @@ public class TestAdmin1 {
       }
     }
   }
+
+  @Test
+  public void testMergeRegions() throws Exception {
+    TableName tableName = TableName.valueOf("testMergeWithFullRegionName");
+    HColumnDescriptor cd = new HColumnDescriptor("d");
+    HTableDescriptor td = new HTableDescriptor(tableName);
+    td.addFamily(cd);
+    byte[][] splitRows = new byte[2][];
+    splitRows[0] = new byte[]{(byte)'3'};
+    splitRows[1] = new byte[]{(byte)'6'};
+    try {
+      TEST_UTIL.createTable(td, splitRows);
+      TEST_UTIL.waitTableAvailable(tableName);
+
+      List<HRegionInfo> tableRegions;
+      HRegionInfo regionA;
+      HRegionInfo regionB;
+
+      // merge with full name
+      tableRegions = admin.getTableRegions(tableName);
+      assertEquals(3, admin.getTableRegions(tableName).size());
+      regionA = tableRegions.get(0);
+      regionB = tableRegions.get(1);
+      admin.mergeRegions(regionA.getRegionName(), regionB.getRegionName(), false);
+      Thread.sleep(1000);
+      assertEquals(2, admin.getTableRegions(tableName).size());
+
+      // merge with encoded name
+      tableRegions = admin.getTableRegions(tableName);
+      regionA = tableRegions.get(0);
+      regionB = tableRegions.get(1);
+      admin.mergeRegions(regionA.getEncodedNameAsBytes(), regionB.getEncodedNameAsBytes(), false);
+      Thread.sleep(1000);
+      assertEquals(1, admin.getTableRegions(tableName).size());
+    } finally {
+      this.admin.disableTable(tableName);
+      this.admin.deleteTable(tableName);
+    }
+  }
 }