The study on herb medicine to reduce the body weight of obese women focus on the factors related (age, frequencies of taking herb medicine and relative body weight) has been done. 63 obese patients at a traditional clinic who took herb medicine were included to be the research samples. Data used were collected by researchers from medical record. The result found that less than 30 years old women group and 31 to 50 years old women group has chance 24.6 and 11.3 times to reduce their body weight compared with more than 50 years old women group. While women who took herb medicine for more than 2 months (1 bag per day) has chance 6.6 times to reduce their body weight compared with one month or less as well. There is no significant evident that relative body weight has impact to body weight reduction. Consider to factors related, the multiple logistic regression method used to formulate the probability of reduction body weight. The study conclution: The herb medicine has effect to the body weight reduction as well as the age group, neither nor the relative body weight. The probability of reduction body weight might be measured regard to formula created. The study recommended to developt a clinical trial to find out the effectiveness of the herb medicine on body weight reduction.