diff --git a/src/main/java/net/onrc/onos/core/intent/IntentMap.java b/src/main/java/net/onrc/onos/core/intent/IntentMap.java
new file mode 100644
index 0000000..ae314a7
--- /dev/null
+++ b/src/main/java/net/onrc/onos/core/intent/IntentMap.java
@@ -0,0 +1,190 @@
+package net.onrc.onos.core.intent;
+
+import java.util.Collection;
+import java.util.EventListener;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Map.Entry;
+
+import net.onrc.onos.core.intent.Intent.IntentState;
+import net.onrc.onos.core.intent.runtime.IntentStateList;
+
+/**
+ * @author Toshio Koide (t-koide@onlab.us)
+ */
+public class IntentMap {
+	private HashSet<ChangedListener> listeners = new HashSet<>();
+	private HashMap<String, Intent> intents = new HashMap<>();
+	private	LinkedList<ChangedEvent> events = new LinkedList<>();
+
+	public enum ChangedEventType {
+		/**
+		 * Added new intent.
+		 */
+		ADDED,
+
+		/**
+		 * Removed existing intent.
+		 * The specified intent is an instance of Intent class (not a child class)
+		 * Only id and state are valid.
+		 */
+		REMOVED,
+
+		/**
+		 * Changed state of existing intent.
+		 * The specified intent is an instance of Intent class (not a child class)
+		 * Only id and state are valid.
+		 */
+		STATE_CHANGED,
+	}
+
+	public class ChangedEvent {
+		public ChangedEvent(ChangedEventType eventType, Intent intent) {
+			this.eventType = eventType;
+			this.intent = intent;
+		}
+		public ChangedEventType eventType;
+		public Intent intent;
+	}
+
+	public interface ChangedListener extends EventListener {
+		void intentsChange(LinkedList<ChangedEvent> events);
+	}
+
+	//================================================================================
+	// public methods
+	//================================================================================
+
+	public void executeOperations(IntentOperationList operations) {
+		for (IntentOperation operation: operations) {
+			switch (operation.operator) {
+			case ADD:
+				handleAddOperation(operation);
+				break;
+			case REMOVE:
+				handleRemoveOperation(operation);
+				break;
+			case ERROR:
+				handleErrorOperation(operation);
+				break;
+			}
+		}
+		notifyEvents();
+	}
+
+	public void purge() {
+		LinkedList<String> removeIds = new LinkedList<>();
+		for (Entry<String, Intent> entry: intents.entrySet()) {
+			Intent intent = entry.getValue();
+			if (intent.getState() == IntentState.DEL_ACK
+					|| intent.getState() == IntentState.INST_NACK) {
+				removeIds.add(intent.getId());
+			}
+		}
+		for (String intentId: removeIds) {
+			removeIntent(intentId);
+		}
+		notifyEvents();
+	}
+
+	public void changeStates(IntentStateList states) {
+		for (Entry<String, IntentState> state: states.entrySet()) {
+			setState(state.getKey(), state.getValue());
+		}
+		notifyEvents();
+	}
+
+	public Intent getIntent(String intentId) {
+		return intents.get(intentId);
+	}
+
+	public Collection<Intent> getAllIntents() {
+		return intents.values();
+	}
+
+	public void addChangeListener(ChangedListener listener) {
+		listeners.add(listener);
+	}
+
+	public void removeChangedListener(ChangedListener listener) {
+		listeners.remove(listener);
+	}
+
+	//================================================================================
+	// methods that affect intents map (protected)
+	//================================================================================
+
+	protected void putIntent(Intent intent) {
+		if (intents.containsKey(intent.getId()))
+			removeIntent(intent.getId());
+		intents.put(intent.getId(), intent);
+		events.add(new ChangedEvent(ChangedEventType.ADDED, intent));
+	}
+
+	protected void removeIntent(String intentId) {
+		Intent intent = intents.remove(intentId);
+		if (intent == null) return;
+		events.add(new ChangedEvent(ChangedEventType.REMOVED, intent));
+	}
+
+	protected void setState(String intentId, IntentState state) {
+		Intent intent = intents.get(intentId);
+		if (intent == null) return;
+		intent.setState(state);
+		events.add(new ChangedEvent(ChangedEventType.STATE_CHANGED, intent));
+	}
+
+	//================================================================================
+	// helper methods (protected)
+	//================================================================================
+
+	protected void handleAddOperation(IntentOperation operation) {
+		putIntent(operation.intent);
+	}
+
+	protected void handleRemoveOperation(IntentOperation operation) {
+		Intent intent = getIntent(operation.intent.getId());
+		if (intent == null) {
+			// TODO error handling
+		}
+		else {
+			setState(intent.getId(), IntentState.DEL_REQ);
+		}
+	}
+
+	protected void handleErrorOperation(IntentOperation operation) {
+		//TODO put error message into the intent
+
+		ErrorIntent errorIntent = (ErrorIntent) operation.intent;
+		Intent targetIntent = intents.get(errorIntent.getId());
+		if (targetIntent == null) {
+			// TODO error handling
+			return;
+		}
+
+		switch (targetIntent.getState()) {
+		case CREATED:
+		case INST_REQ:
+		case INST_ACK:
+		case REROUTE_REQ:
+			setState(targetIntent.getId(), IntentState.INST_NACK);
+			break;
+		case DEL_REQ:
+			setState(targetIntent.getId(), IntentState.DEL_PENDING);
+			break;
+		case INST_NACK:
+		case DEL_PENDING:
+		case DEL_ACK:
+			// do nothing
+			break;
+		}
+	}
+
+	protected void notifyEvents() {
+		for (ChangedListener listener: listeners) {
+			listener.intentsChange(events);
+		}
+		events.clear();
+	}
+}