This study discusses third grade elementary school children¡¦s growth in mathematics ability through a mathematics curriculum integrated with problem posing. By applying action research method, this study tries to find out the participating teacher¡¦s progress in her teaching method. In particular, also to find out the problems that may arise from carrying out problem- posing instruction, the possible solutions to these problems, and the problem-posing activities that can be readily applied in classroom setting. The time this study takes, from identifying the problem to the point of retreating from the research setting, is about one year. During this year, the investigator used various methods to collect data: interviews, video recordings of class teaching, teachers¡¦ notes and recordings, and children mathematics diaries. He included research-related surveys and triangulation for data analysis. It is found that, the teacher has to do more than having a firm grasp of the teaching materials, but also to attend to the teaching processes, the timing of introducing the critical questions related to the main points, and the ability to conduct a discussion atmosphere that is conducive for the students¡¦ growth. Most important of all, the mindset has to be changed from a teacher-oriented one to a more student-oriented set. Compared to the original teaching without problem posing, it is found that students became more active in class discussions, and showed more logic in their solutions. They debated about mathematics problems instead of aimless quarreling. Moreover, the content of the problem-posing products become more creative and no longer mechanical. In addition, students¡¦ solution processes were no longer by imitation, but instead, showing expressions of elaborated thoughts. All these show that the integration of problem-posing instruction has increased students¡¦ interests and motivation in studying mathematics.