Objective To investigate the influence of 1oganin on proliferation and differentiation of rat preadipocytes. Methods Rat preadipocytes were cultured. The proliferation of rat preadipoeytes was detected by MTT method. The expression of GPDH during the preadipoeytes differentiation was determined by using enzyme tissue chemical way, and the accumulation of cellular lipid was determined by Oil Red O staining. Results Loganin at the concentrations of 8, 16, 32 ? mol/L stimulated rat preadipocyte proliferation, inhibited GPDH increase and lipid accumulation during differentiation in a concentration-dependent manner. Conclusion Loganin can stimulate rat preadipocyte proliferation, inhibite rat preadipocyte differentiation.