Research on mediation system in Law circles is sufficient, while the study on mediator especially for case analysis is less. Hypothetically, mediator in ethnic minority areas should have the following characteristics:legal personality, political role, pragmatic role and the role of minority. Through the field investigation, the theoretical presupposition could be verified. There are defects exited in the presupposition which include lacking of trust and the role of imbalance. Based on this, we rethink the Mediation Law and put forward some suggestions.