The purpose of this research is to investigate the strategies for problem solving used by teachers and students and obtain some information which would be useful to enhance the ability of problem solving of the students. For this purpose we apply the thinking aloud method to study 6 graders and 6 teachers who were asked to solve 5 word problems. And we create a coding system to analyze those strategies. Using this coding system, we code the examinees and problems. we come up with the following facts from our study. (1) The number of strategies used by teachers is less than that used by students. (2) The characteristic of the strategies used by students is to set up an equation. (3) There is deep relationship between understanding the question and choosing the successful strategies for problem solving. (4) The students use the inductive argument more often than the teachers in the case of nonroutine mathematical problem. (5) The student of high success rate have fewer strategies than the others. From the above facts. it proposes the following conclusion for the enhancement of the ability of problem solving: So far the teachers usually use a few typical strategies for problem solving. But they need to create various strategies for pqoblem solving. It makes it possible for the students to choose proper strategies according to their ability. The students need to be given nicely constructed problem with enough time.