diff --git a/pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/ComponentImpl.java b/pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/ComponentImpl.java
index c7d227890cb44..41b4c52c581e1 100644
--- a/pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/ComponentImpl.java
+++ b/pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/ComponentImpl.java
@@ -1235,15 +1235,17 @@ public void putFunctionState(final String tenant,
         try {
             DefaultStateStore store = worker().getStateStoreProvider().getStateStore(tenant, namespace, functionName);
             ByteBuffer data;
-            if (state.getStringValue() != null) {
-                data = ByteBuffer.wrap(state.getStringValue().getBytes(UTF_8));
-            } else if (state.getByteValue() != null) {
-                data = ByteBuffer.wrap(state.getByteValue());
-            } else if (state.getNumberValue() != null) {
-                data = ByteBuffer.allocate(Long.BYTES);
-                data.putLong(state.getNumberValue());
+            if (state.getByteValue() == null || state.getByteValue().length == 0) {
+                if (state.getStringValue() != null) {
+                    data = ByteBuffer.wrap(state.getStringValue().getBytes(UTF_8));
+                }  else if (state.getNumberValue() != null) {
+                    data = ByteBuffer.allocate(Long.BYTES);
+                    data.putLong(state.getNumberValue());
+                } else {
+                    throw new IllegalArgumentException("Invalid state value");
+                }
             } else {
-                throw new IllegalArgumentException("Invalid state value");
+                data = ByteBuffer.wrap(state.getByteValue());
             }
             store.put(key, data);
         } catch (Throwable e) {
diff --git a/tests/integration/src/test/java/org/apache/pulsar/tests/integration/functions/PulsarStateTest.java b/tests/integration/src/test/java/org/apache/pulsar/tests/integration/functions/PulsarStateTest.java
index f44cdffe6399d..856e4edfea023 100644
--- a/tests/integration/src/test/java/org/apache/pulsar/tests/integration/functions/PulsarStateTest.java
+++ b/tests/integration/src/test/java/org/apache/pulsar/tests/integration/functions/PulsarStateTest.java
@@ -28,6 +28,7 @@
 import static org.testng.Assert.expectThrows;
 import static org.testng.Assert.fail;
 import com.google.common.base.Utf8;
+import com.google.gson.Gson;
 import java.util.Base64;
 import lombok.Cleanup;
 import lombok.extern.slf4j.Slf4j;
@@ -112,6 +113,20 @@ private void doTestPythonWordCountFunction(String functionName) throws Exception
         String expectNumber = "\"numberValue\": 20";
         putAndQueryState(functionName, "test-number", numberState, expectNumber);
 
+        byte[] valueBytes = Base64.getDecoder().decode(VALUE_BASE64);
+        String bytesString = Base64.getEncoder().encodeToString(valueBytes);
+        String byteState = "{\"key\":\"test-bytes\",\"byteValue\":\"" + bytesString + "\"}";
+        putAndQueryStateByte(functionName, "test-bytes", byteState, valueBytes);
+
+        String valueStr = "hello pulsar";
+        byte[] valueStrBytes = valueStr.getBytes(UTF_8);
+        String bytesStrString = Base64.getEncoder().encodeToString(valueStrBytes);
+        String byteStrState = "{\"key\":\"test-str-bytes\",\"byteValue\":\"" + bytesStrString + "\"}";
+        putAndQueryState(functionName, "test-str-bytes", byteStrState, valueStr);
+
+        String byteStrStateWithEmptyValues = "{\"key\":\"test-str-bytes\",\"byteValue\":\"" + bytesStrString + "\",\"stringValue\":\"\",\"numberValue\":0}";
+        putAndQueryState(functionName, "test-str-bytes", byteStrStateWithEmptyValues, valueStr);
+
         // delete function
         deleteFunction(functionName);
 
@@ -539,6 +554,33 @@ private void putAndQueryState(String functionName, String key, String state, Str
         assertTrue(result.getStdout().contains(expect));
     }
 
+    private void putAndQueryStateByte(String functionName, String key, String state, byte[] expect)
+            throws Exception {
+        container.execCmd(
+                PulsarCluster.ADMIN_SCRIPT,
+                "functions",
+                "putstate",
+                "--tenant", "public",
+                "--namespace", "default",
+                "--name", functionName,
+                "--state", state
+        );
+
+        ContainerExecResult result = container.execCmd(
+                PulsarCluster.ADMIN_SCRIPT,
+                "functions",
+                "querystate",
+                "--tenant", "public",
+                "--namespace", "default",
+                "--name", functionName,
+                "--key", key
+        );
+
+        FunctionState byteState = new Gson().fromJson(result.getStdout(), FunctionState.class);
+        assertNull(byteState.getStringValue());
+        assertEquals(byteState.getByteValue(), expect);
+    }
+
     private void publishAndConsumeMessages(String inputTopic,
                                                   String outputTopic,
                                                   int numMessages) throws Exception {