Abstract: How to improve the efficiency of service matchmaking algorithm to provide service discovery is a key problem along with the development and application of service. But the existing way in matching still depend on the semantic matchmaking mechanism by which the service stays at an atom-like level. With the internal logic of service becomes more and more complex, the big-grain-size service emerges, which requires a behavioral description for the complex business logic because the existing matchmaking algorithms are incompatible with the matchmaking of such a service. Characterizing the behavior of service, a relevant matchmaking algorithm based on behavioral effect is proposed. The behavioral effect is defined including event, precondition and result, and then they are matched with each other to compute what the users demand and the matching accuracy between description and service required. Experimental results verify the feasibility and effectiveness of the algorithm proposed.