diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/ProgramCounter.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/ProgramCounter.java
new file mode 100644
index 0000000..6af50e0
--- /dev/null
+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/ProgramCounter.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.workflow.api;
+
+import java.util.Objects;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * An interface representing workflow program counter.
+ */
+public final class ProgramCounter {
+
+    public static final ProgramCounter INIT_PC = ProgramCounter.valueOf(Worklet.Common.INIT.name(), 0);
+
+    /**
+     * index of the worklet.
+     */
+    private int workletIndex;
+
+    /**
+     * Type of worklet.
+     */
+    private String workletType;
+
+    /**
+     * Index of worklet.
+     * @return index of worklet
+     */
+    public int workletIndex() {
+        return this.workletIndex;
+    }
+
+    /**
+     * Type of worklet.
+     * @return type of worklet
+     */
+    public String workletType() {
+        return this.workletType;
+    }
+
+    /**
+     * Constructor of workflow Program Counter.
+     * @param workletType type of worklet
+     * @param workletIndex index of worklet
+     */
+    private ProgramCounter(String workletType, int workletIndex) {
+        this.workletType = workletType;
+        this.workletIndex = workletIndex;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.toString());
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) {
+            return true;
+        }
+        if (!(obj instanceof ProgramCounter)) {
+            return false;
+        }
+        return Objects.equals(this.workletType(), ((ProgramCounter) obj).workletType())
+                && Objects.equals(this.workletIndex(), ((ProgramCounter) obj).workletIndex());
+    }
+
+    @Override
+    public String toString() {
+        return String.format("(%d)%s", workletIndex, workletType);
+    }
+
+    /**
+     * Builder of workflow Program Counter.
+     * @param workletType type of worklet
+     * @param workletIndex index of worklet
+     * @return program counter
+     */
+    public static ProgramCounter valueOf(String workletType, int workletIndex) {
+        return new ProgramCounter(workletType, workletIndex);
+    }
+
+    /**
+     * Builder of workflow Program Counter.
+     * @param strProgramCounter string format for program counter
+     * @return program counter
+     */
+    public static ProgramCounter valueOf(String strProgramCounter) {
+
+        Matcher m = Pattern.compile("\\((\\d+)\\)(.+)").matcher(strProgramCounter);
+
+        if (!m.matches()) {
+            throw new IllegalArgumentException("Malformed program counter string");
+        }
+
+        return new ProgramCounter(m.group(2), Integer.parseInt(m.group(1)));
+    }
+
+}
+