Background : The safety of Korean herbal Medicine (KHM: prescribed herbal medicine by doctors of traditional Korean medicine) is an important issue in Korea. Although both fields. western medicine and traditional Korean medicine. have been studied on the safety of herbs and KHM, their results were not concordance with each other. Objectives : This study aims to review the influence of KHM on liver function in Korean literature systematically. Additionally, we tried to estimate the change of data of liver function test (LFT) and the incidence of liver injury (LI) after the use of KHM. Methods : Systematic literature searches were performed on 4 major databases of Korea from their inception to May 2008. Screening and selection of the studies and the extraction of data were performed independently by two authors. There were no restrictions on the types of publication including grey literatures. Results : Forty studies were included. Only sixteen studies were performed prospectively and fifteen studies collected data from outpatients. Only 8 studies reported the occurrence of LI after the use of KHM. Nineteen cases of LI showed no or mild symptoms and the elevation of LFT was not high. All of LI patients used conventional western drug and KHM concomitantly. and causality of LI was not assessed properly. The incidence of LI related to the use of KHM was estimated as 0.59%-0.76% from all data of these studies. The conflicting results were shown on the change of alanine aminotransferase (ALT) and total bilirubin (TB) after the use of KHM. Conclusions : KHM might be a minor cause of LI in Korea. However the results are not strongly supported as enough to make the safety issue clear because of the limitations of original studies. More rigorous studies are required for answering the safety issue of KHM with the cooperative investigation of both fields of Korean traditional medicine and western medicine.