Purpose: This study investigated the effect of microwave diathermy against the body composition of obese women with protein content, muscle quantity, and the change of body weight for three weeks by microwave diathermy. Methods: we performed the change of body weight for three weeks using the method of 100,000 Hz microwave diathermy against obese women. The obese women were examined the change of body weight by pre-test using microwave diathermy. Results: The effect of microwave diathermy in protein content, muscle quantity, and body weight did not show any statistically significant in an experimental group of eight female university students for three weeks, but the change of body weight was statistically significant (p>0.05) for three weeks to eight students who were examined by microwave diathermy. The control group did not show any statistically significant in protein content, muscle quantity, body fat, and the change of body weight for three weeks.s). Conclusion: These results suggest that microwave diathermy may be an effective method for the management of the body and the diet in obese women.