comparing with the judgment, the mediation plays an important role in dealing with the civil cases for people’s court; most of the people still know little about the basis, reason, factors and mechanism about mediation in the second trial. To analyze the contract case through empirical study, this paper lists and charts the symbols of the contract cases which is mediated in the course of second trial, demonstrates the constitution of the social cost on mediation, and concludes that the cost consumption of mediation is less than that of judicial procedure. So the second mediation judgment is more efficient. Because the second judgment or mediation system is based on reviewing of all the facts and the law application, so it is very important to the judgment in the first trial. This paper proves that the existence of causal relation instance in the success of mediation cases and a judgment result helps judge recognize the second-trial contract cases which can be prior tried by mediation way process. It also proved that mediation is optimum solution when the contract cases with some special characteristics..