Purpose: This study was done to investigate the effect of Tai Chi Qigong exercise program on insulin resistance and blood glucose in patients with type 2 diabetes. Method: This was a quasi-experimental study used a non-equivalent control group pretest-posttest design. Participants included 39 patients with type 2 diabetes mellitus patients (ages between 40-70)(experimental group, 19, control group, 20). The Tai Chi Qigong exercise program consisted of 5 minute warming up, 30-minute main exercise, and 5 minute cooling down, and was conducted twice a week for 10 weeks. The outcome variables were insulin resistance (proinsulin, C-peptide, insulin, insulin sensitivity index) and blood glucose (fasting, post prandial 2hr, HbA1c). Data was analyzed using ANCOVA, with pre-test values as covariates, to examine difference between pre and post measures between the two groups. Results: The Tai Chi Qigong was effective in lowering postprandial 2hr blood glucose. Conclusion: Twice a week 10 week-Tai Chi Qigong exercise seems to be too short to improve insulin excretion or resistance, and fasting blood sugar and HbA1C in patients with type 2 DM. A Tai Chi Qigong program at least 3 times per week or longer is recommended.