Abstract: When business processes are mostly supported by information systems, the availability of event logs generated from these systems and the requirements of appropriate process models are increasing. However, some events cannot be correctly identified because of the explosion of the amount of event logs. Conformance checking techniques can be used to detect and diagnose the differences between observed and modeled behavior, but they cannot repair the actual model. The information from conformance checking can be used for model repair. By means of the firing sequences of event logs, process models can be repaired from three aspects: removing behavior, adding behavior and changing behavior. The structure with deleted activity in process model, the relationship between additional activities and adjoin activities, and the nonconformance sub-process in process model should be identified when the process model need repairing. It is obtained that the repaired model can replay (most of) event logs based on the proposed techniques, and it is as similar to the original model as possible. The methods in this paper are simulated manually. A real-world process model of hospitalization in a hospital and the corresponding event logs are employed to evaluate the proposed approaches. The correctness and effectiveness of the proposed methods are illustrated through experiments.