diff --git a/src/test/java/net/onrc/onos/util/GraphDBOperationTest.java b/src/test/java/net/onrc/onos/util/GraphDBOperationTest.java
new file mode 100644
index 0000000..f6e2a81
--- /dev/null
+++ b/src/test/java/net/onrc/onos/util/GraphDBOperationTest.java
@@ -0,0 +1,304 @@
+/**
+ * 
+ */
+package net.onrc.onos.util;
+
+import static org.junit.Assert.*;
+
+import net.floodlightcontroller.core.INetMapTopologyObjects.ISwitchObject;
+import net.floodlightcontroller.core.ISwitchStorage.SwitchState;
+import net.floodlightcontroller.core.internal.TestDatabaseManager;
+import net.onrc.onos.util.GraphDBConnection.Transaction;
+
+import org.easymock.EasyMock;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.api.easymock.PowerMock;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import com.thinkaurelius.titan.core.TitanFactory;
+import com.thinkaurelius.titan.core.TitanGraph;
+
+/**
+ * @author Toshio Koide
+ *
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({TitanFactory.class})
+public class GraphDBOperationTest {
+	private static TitanGraph titanGraph;
+	private static GraphDBConnection conn;
+	private static GraphDBOperation op;
+
+	/**
+	 * @throws java.lang.Exception
+	 */
+	@BeforeClass
+	public static void setUpBeforeClass() throws Exception {
+	}
+
+	/**
+	 * @throws java.lang.Exception
+	 */
+	@AfterClass
+	public static void tearDownAfterClass() throws Exception {
+	}
+
+	/**
+	 * @throws java.lang.Exception
+	 */
+	@Before
+	public void setUp() throws Exception {
+		TestDatabaseManager.deleteTestDatabase();
+		titanGraph = TestDatabaseManager.getTestDatabase();
+//		TestDatabaseManager.populateTestData(titanGraph);
+		
+		// replace return value of TitanFactory.open() to dummy DB created above
+		PowerMock.mockStatic(TitanFactory.class);
+		EasyMock.expect(TitanFactory.open((String)EasyMock.anyObject())).andReturn(titanGraph);
+		PowerMock.replay(TitanFactory.class);
+		
+		conn = GraphDBConnection.getInstance("/dummy/to/conf");
+		op = new GraphDBOperation(conn);
+	}
+
+	/**
+	 * @throws java.lang.Exception
+	 */
+	@After
+	public void tearDown() throws Exception {
+		conn.close();
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#newSwitch(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testNewSwitch() {
+		Iterable<ISwitchObject> switches;
+
+		switches = op.getAllSwitches();
+		assertFalse(switches.iterator().hasNext());
+
+		ISwitchObject sw = op.newSwitch();
+		sw.setType("switch");
+		sw.setDPID("123");
+		sw.setState(SwitchState.ACTIVE.toString());
+		conn.endTx(Transaction.COMMIT);
+
+		switches = op.getAllSwitches();
+		assertTrue(switches.iterator().hasNext());
+		
+		ISwitchObject obtained_sw = switches.iterator().next();
+		String obtained_dpid = obtained_sw.getDPID(); 
+		assertEquals("123", obtained_dpid);
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#removeSwitch(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.ISwitchObject)}.
+	 */
+	@Test
+	public final void testRemoveSwitch() {
+		Iterable<ISwitchObject> switches;
+
+		// make sure there is no switch
+		switches = op.getAllSwitches();
+		assertFalse(switches.iterator().hasNext());
+
+		
+		ISwitchObject sw = op.newSwitch();
+		sw.setType("switch");
+		sw.setDPID("123");
+		sw.setState(SwitchState.ACTIVE.toString());
+		conn.endTx(Transaction.COMMIT);
+
+		switches = op.getAllSwitches();
+		assertTrue(switches.iterator().hasNext());
+		
+		ISwitchObject obtained_sw = switches.iterator().next();
+		String obtained_dpid = obtained_sw.getDPID(); 
+		assertEquals("123", obtained_dpid);
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchSwitch(net.onrc.onos.util.GraphDBConnection, java.lang.String)}.
+	 */
+	@Test
+	public final void testSearchSwitch() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchDevice(net.onrc.onos.util.GraphDBConnection, java.lang.String)}.
+	 */
+	@Test
+	public final void testSearchDevice() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchPort(net.onrc.onos.util.GraphDBConnection, java.lang.String, short)}.
+	 */
+	@Test
+	public final void testSearchPort() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#newPort(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testNewPort() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#newDevice(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testNewDevice() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#removePort(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.IPortObject)}.
+	 */
+	@Test
+	public final void testRemovePort() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#removeDevice(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.IDeviceObject)}.
+	 */
+	@Test
+	public final void testRemoveDevice() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getDevices(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetDevices() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchFlowPath(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.util.FlowId)}.
+	 */
+	@Test
+	public final void testSearchFlowPath() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#newFlowPath(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testNewFlowPath() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#removeFlowPath(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.IFlowPath)}.
+	 */
+	@Test
+	public final void testRemoveFlowPath() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getFlowPathByFlowEntry(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.IFlowEntry)}.
+	 */
+	@Test
+	public final void testGetFlowPathByFlowEntry() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getAllFlowPaths(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetAllFlowPaths() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchFlowEntry(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.util.FlowEntryId)}.
+	 */
+	@Test
+	public final void testSearchFlowEntry() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#newFlowEntry(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testNewFlowEntry() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#removeFlowEntry(net.onrc.onos.util.GraphDBConnection, net.floodlightcontroller.core.INetMapTopologyObjects.IFlowEntry)}.
+	 */
+	@Test
+	public final void testRemoveFlowEntry() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getAllFlowEntries(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetAllFlowEntries() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getAllSwitchNotUpdatedFlowEntries(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetAllSwitchNotUpdatedFlowEntries() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getActiveSwitches(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetActiveSwitches() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getAllSwitches(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetAllSwitches() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#getInactiveSwitches(net.onrc.onos.util.GraphDBConnection)}.
+	 */
+	@Test
+	public final void testGetInactiveSwitches() {
+		fail("Not yet implemented");
+	}
+
+	/**
+	 * Test method for {@link net.onrc.onos.util.GraphDBOperation#searchActiveSwitch(net.onrc.onos.util.GraphDBConnection, java.lang.String)}.
+	 */
+	@Test
+	public final void testSearchActiveSwitch() {
+		fail("Not yet implemented");
+	}
+
+}