This study is designed to report the correlation between Body Mass Index(BMI), Heart Rate Variability(HRV), stess, drinking alcohol, coffee and smoking. Methods From 1st January 2010 to 31st December 2012, We tested on 458 patients who hospitalized in Cheong Yeon Korean Medicine Hospital for reducing their weights, then we collected the statistical analysis with the result of their HRV and the special survey. Results This experiment was studied on total 458 patients, 27 were men and 431 were women. The average of the age of men was 28.23±4.22 and 24.31±385 was women. There were significant differences in BMI, Low frequency(LF), High frequency(HF), stress score, frequency of drinking alcohol, smoking and drinking coffee followed by their ages. When we looked at the correlation between obesity with smoking and drinking coffee, we can see that the BMI increased, the frequency of drinking alcohol was decreased, however there were no statistic correlation in smoking and drinking coffee with BMI. Conclusions With the result of HRV, we can suggest the BMI and stress score are correlated each other but we need further studies about passive stress relief by taking favourite food such as drinking alcohol, smoking, drinking coffee, etc.