diff --git a/CHANGES.txt b/CHANGES.txt
index eb157ce49d7..b4f15fb078c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -399,6 +399,8 @@ Release 0.90.4 - Unreleased
    HBASE-4045  [replication] NPE in ReplicationSource when ZK is gone
    HBASE-4034  HRegionServer should be stopped even if no META regions
                are hosted by the HRegionServer (Akash Ashok)
+   HBASE-4033  The shutdown RegionServer could be added to
+               AssignmentManager.servers again (Jieshan Bean)
 
   IMPROVEMENT
    HBASE-3882  hbase-config.sh needs to be updated so it can auto-detects the
diff --git a/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java b/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
index bde5f485c8d..9b5a0215670 100644
--- a/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
+++ b/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
@@ -882,9 +882,15 @@ public class AssignmentManager extends ZooKeeperListener {
       ServerName oldSn = this.regions.get(regionInfo);
       if (oldSn != null) LOG.warn("Overwriting " + regionInfo.getEncodedName() +
         " on " + oldSn + " with " + sn);
-      this.regions.put(regionInfo, sn);
-      addToServers(sn, regionInfo);
-      this.regions.notifyAll();
+      
+      if (isServerOnline(sn)) {
+        this.regions.put(regionInfo, sn);
+        addToServers(sn, regionInfo);
+        this.regions.notifyAll();
+      } else {
+        LOG.info("The server is not in online servers, ServerName=" + 
+          sn.getServerName() + ", region=" + regionInfo.getEncodedName());
+      }
     }
     // Remove plan if one.
     clearRegionPlan(regionInfo);
@@ -2364,4 +2370,11 @@ public class AssignmentManager extends ZooKeeperListener {
   public void stop() {
     this.timeoutMonitor.interrupt();
   }
+  
+  /**
+   * Check whether the RegionServer is online.
+   */
+  public boolean isServerOnline(ServerName serverName) {
+    return this.serverManager.isServerOnline(serverName);
+  }
 }