Purpose: This study was to evaluate the effects of a short term comprehensive life style modification program on glycemic metabolism, lipid metabolism and body composition in type 2 diabetes mellitus patients. Method: A nonequivalent control group with a pre post test was designed. Data collection was done from October 2003 to June, 2004 at a hospital. Glycemic metabolism was measured by a.c., p.c. and $HbA_{1}c$, and lipid metabolism was measured by cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. Body Composition was measured by body weight, body mass index, waist, measurement waist per hip ratio, body fat, muscle weight and abdominal fat tissue(intra abdominal distance). The Experimental group, which was composed of 29 participants, was educated based on a life style modification protocol at a weekly meeting for 12 weeks and carried out exercise, diet along individual parameters and self monitoring, while 24 participants in the control group received only diet education. Result: 1. The experimental group showed a significant lower a.c.(t=2.11, p=.04) and $HbA_{1}c$(t=2.65, p=.01) compared to those of the control group. 2. The experimental group showed a significant lower LDL than the results of the control group(t=2.42, p=.02). 3. The experimental group showed a significant lower weight(t=3.09, p=.00), BMI(t=3.01, p=.00), body fat(t=2.94, p=.01) and abdominal fat tissue(t=3.05, p=.01) than those of the control group. Conclusion: The results provided evidence for the effectiveness of a short term comprehensive life style modification program composed of exercise, diet, support, self efficacy elevation and self monitoring in type 2 diabetes mellitus.