Debugging the distributed applications is very difficult. One of the reasons why this problem is made is that the distributed applications are inherently more complex than sequential ones. To solve this problem, the method of abstracting events is proposed, which lets the users grasp the various aspects of behaviors of a distributed application. Abstract event timestamp is used to decide the “happened before” relation among abstract events, which plays a very important role in abstracting and debugging the distributed applications. In this paper, a new complete algorithm of timestamping abstract event is proposed, which needs less storage and costs less time than others. Proofs of the correctness of the algorithms are also given in this paper.