The aim of this study is to investigate the influence of graphic calculator in the teaming of function of the underachieved students in the second grade of middle school. Under this purpose of the study, we devised the instruction-plan which incorporates the using of graphic calculator into the traditional paper-and-pencil teaming environments, and executed the function-instruction with the underachieved students according to the devised instruction-plan. During the lesson hours, we observed and analysed the contributions and the carefulness of using graphic calculator in the learning of function of the underachieved students. Furthermore, we carried out the pre-test and the post-test to examine the effects of using graphic calculator in the learning of function of the underachieved students.