BACKGROUND AND AIMS: Syrian hamsters are commonly used as a model for experimental induction of gallstones, In Korea, there has been no report on the animal model of cholesterol gallstone using Syrian hamsters. The aims of the present study were to evaluate the influence of cholesterol rich diet on the formation of gallstones in hamster bred in Korea and to establish an adequate animal model of cholesterol gallstones. METHODS: Male golden Syrian hamsters were randomly divided into the two groups and fed either conventional semipurified diet (SPD) (control group: n= 10) or SPD containing 0.3% cholesterol (high-cholesterol diet group: n= 20). After feeding for 6 weeks, the hamsters were sacrificed. Then, the formation of gallstones or crystals was examined and the composition of formed gallstone was analyzed. Serum and bibary cholesterol level, bile composition, and cholesterol saturation index (CSI) of the control and the high-cholesterol diet group were compared. RESULTS: Liver weights of the high-cholesterol diet group were greater than those of the control poup (p<0.05). In high-cholesterol diet group, gallstones were formed in 12 out of 20 hamsters (60%) and cholesterol crystals were noted in 16 out of 20 (80%). On the other hand, the control hamsters developed neither gallstones nor cholestcrol crystals (p<0.01). Upon analysis of the gallstones, all the stones contained 95% or more cholesterol. The serum and biliary cholesterol levels and CSI were significantly higher in high-holesterol diet group than in control group (p<0,01). In high-cholesterol diet group, both chenodeoxy-cholic acid (CDCA) and lithocholic acid (LCA) were higher and cholic acid (CA) was lower than in the control group (p<0.01). CONCLUSIONS: Dietary induction of cholesterol gallstones in hamster using semipurified diet containing 0.3% cholesterol was successful in golden Syrian hamster bred in Korea. Cholesterol supersaturation of bile may play a role in the formation of gallstones.