In this paper to prevent human errors analyzed the causes of railway accidents and human error in last 5 years(2007~2011). The 2nd Railway Comprehensive Safety Plan currently being implemented in the safety business for prevention of human error. The accidents are often resulted from multiple causes with hardware failure and human errors. And prevention of human error associated with the implementation details of the priority projects, 14 projects were selected by draw. Then Analytic Hierarchy Process(AHP) methodology was used to select what projects were effective to human error.