Objectives : This study was done to investigate the relativity of thermography to HRV(heart rate variability) in Sasang constitutional groups. Methods : We investigated 87 healthy workers consisted of 10 Taeumin, 47 Soeumin, 30 Soyangin. After diagnosing the Sasang constitution by QSCCII(Questionnaire for the Sasang Constitutional Classification), we ana lysed their HRV -time domain and frequency domain and also checked their thermography in April 2009. Results & Conclusions : Analysing the thermography, The whole skin temperature was showed equaly in many Taeumin, the face, Upper burner skin temperature was showed high in many Soeumin, and the abdomen skin temperature was showed low in many Soyangin. The relativity of the sympathetic index to skin temperature was high in Taeumin. The higher sympathetic index, the higher Upper burner skin temperature in Taeumin, the higer most of the skin temperature in Soyangin, lower the whole skin temperature in Soeumin.