Physical activity is one of important factors of the chronic disease. It was reported that Most of Korean workers didn't take exercise regularly. The purpose of this study is testing effects of exercise program, based on the Theory of Planned Behavior. 30 subjects participating in this study are workers in small enterprises and have not taken exercise regularly. Exercise program, which includes education, support, monitoring, and counseling, was conducted for 6 weeks. Effects of this program was evaluated by the change of exercise, attitude, subjective norm, perceived control, intention of exercise, perceived health states, and fatigue. The results of this study can be summarized as follows: 1. There was the significant difference between pre and post-test in the subjective norm, perceived control, and intention of exercise, but not the significant difference in the attitude of exercise. 2. 53.3% of the subject of this study had taken exercise regulary in the post-test. 3. There was not the significant difference in the perceived health states and fatigue. From the results, it can be concluded that the exercise program is effective, leading to the change of intention and exercise rate. On the other hand, it was not effective in Physiological aspects. It seems that these result was due to short term program. Thus, it can be recommended that studies are needed with longer term program and larger sample.