Purpose: The aim of this study is to evaluate the effects of community based chronic disease management program for managing hypertension and diabetes mellitus. Method: The subjects of this study were 1,000 clients, who participated in a city community based chronic disease management program. The data were collected by a phone survey directly, and selected from DB of community based chronic disease management program, indirectly. The data were analyzed by the STATA program, using descriptive statistics, t-test, and Multiple regression analysis. Results: The mean score of knowledge of hypertension was 4.33 and diabetes mellitus was 2.52. The affecting factors of knowledge of hypertension were the clinic visiting point and blood sugar. However, the affecting factors of knowledge of diabetes mellitus was core lab point, diastolic blood pressure, and blood sugar. Conclusion: the results of this study showed that knowledge of hypertension increased with higher level of education, and younger ages, while knowledge of diabetes mellitus increased with higher level education, more core lab point, younger ages, and in males. Therefore, to control the chronic diseases more effectively in a community, it is important to develop a more systematic education and self- managing programs, using collaboration of health centers and local clinics.