The purpose of this research is to explore teachers` role actions in teaching mathematical problem solving and to analyze the influences of the teachers` role actions on their students` activities and beliefs about problem solving. The results obtained in this study suggested that the teachers` role actions brought qualitative differences to students` activities, and students` beliefs about mathematical problem solving were consistent with the perspective held by their teachers. Therefore, teachers should help students build up desirable beliefs about problem solving. They should understand teaching mathematical problem solving and play proper roles in various situations of teaching mathematical problem solving.