This study examined the effects of prompts, environmental alteration, and feedback on reduction of food wastes. The study was conducted at a student restaurant at a university. Subjects in this study were college students, faculty members and administrative staffs at the university. An A-BC-BCD-BC within subject design was employed. After baseline phase(A), prompts and environmental alteration were manipulated in the second phase(BC). In the next phase(BCD), feedback was added in addition to the prompts and environmental alteration. In the last phase(B), all the treatments except environmental alteration were withdrawn. The dependent variables n cluded (1) total weight of food waste per day, (2), the weight of food waster per person, (3) the ratio of food waste to total food served per day, (4) total amount of monetary value for food waste to total food served per day. The results indicated that prompts and environmental alteration were affective in reducing food wastes. Thus, measures of all the dependent variables decreased when environmental alteration and prompts were manupulated. However, when feedbacks were added to prompts and environmental alteration, the additional effect of feedback was not observed. The implications and limitations of these findings were discussed and the directions of future studies were also proposed.