Purpose : To identify factors related to the severity and frequency of hot flush of postmenopausal women who participated in a clinical trial. Methods : A cross-section study of 34 postmenopausal women between 40 and 60 years of age was done. VAS(visual analog scale) was used to evaluate the hot flush degree. Statistical analysis was performed with multiple linear regression analysis. Results : Hot flush VAS was proportional to the percent body fat with 1.467 regression coefficient (p-value= 0.010). It implies that the symptom of hot flush becomes worse as the percent body fat increases. Some hormones also have effects on hot flush. We found that LH might cause increment of hot flush VAS(i.e., the corresponding regression coefficient is 0.912). Sasang constitution was not relevant to the hot flush degree. Hot flush VAS seemed to increase as the vascular aging degree by SA-2000 getting worse, but it was not statistically significant (p-value= 0.594). Conclusion : This study is a part of a prospective clinical trial. For more accurate result, larger-scale cross-section study or clinical trial are necessary.