1. Objective The aim of this study was to survey the adverse reactions by the prescriptions of Soeumin.Soyangin and to compare the tendency of their symptoms according to Sasang constitutional type. 2. Methods The clinical data for this study were based on the medical records of total 91 cases collected from an oriental clinic during 1996-2004. Their constitutional types were diagnosed by a specialist and then confirmed by drug reactions. To evaluate reliability of the analysis, we only analysed the cases above grade C. The target prescriptions were Palmulgunja-tang, Bojungikgi-tang, Hyangsayangwi-tang, Ijung-tang, Hyeongbangsabaek-san, Jeoryeongchajeonja-tang, Yanggyeoksanhwa-tang, Yangdokbaekho-tang and the sorts of Jihwang-tang. 3. Results and Conclusion The prescriptions which were not suitable for their Sasang constitutional type induced indigestion, stomachache and evacuation troubles basically. Besides, the prescriptions of Soeumin caused some fever of the upper body and skin on Taeeumin and Soyangin. And the prescriptions of Soyangin lead to more severe digestive and evacuation troubles on Taeeumin and Soeumin. 4. Conclusion: This study need to be compensated by additional clinical studies which are more systematic and continuous. This way we can make the firm evidence for approving the difference of drug susceptibility according to the Sasang constitutional type.