Garcinia extract was used as a potential anti-obesity agent. In this study, we found that Garcinia extract inhibits the cytoplasmic lipid accumulation as well as adipogenic differentiation of preadipocytes. The mechanisms that regulate the inhibition of insulin-induced differentiation by Garcinia extracts include the inhibition of expression of the early adipogenic transcription factor, CCAAT element binding protein (C/EBP)alpha that regulate adipogenesis. These results suggest that the specific targets of Garcinia extract on differentiation process of 3T3-L1 cells could be, at least, early adipogenic differentiation factor.