According to the theory of planned behavior with moral obligation proposed by Beck and Ajzen (1991), the purpose of this study was to explore the current situation of cheating, to construct the structural model of cheating, and to establish a longitudinal effect model of cheating in two waves data of Taiwanese students. Population were public junior and senior high school students in Taiwan and participants were 1,168 students. Utilizing the structural equation modeling, the results were as follows. First, the structural model of cheating indicated a reasonable goodness-of-fit. Second, attitude, perceived behavioral control and moral obligation can significantly predict cheating intention directly and can significantly predict cheating behavior indirectly through cheating intention; cheating intention can also significantly predict cheating behavior directly. Third, the theory of planned behavior structural model of cheating had longitudinal effects; the current cheating intention can significantly predict cheating behavior in the future. The suggestions of the findings were made for educational authorities, and future researchers.