Objectives：To study the effect of Dai Zong Fang（DZF） on 3T3-L1 preadipocytes differentiation and changes in expression of differentiation associated genes. Methods：3T3-L1 preadipocytes cells were induced into mature adipocytes by Cocktail（1-methyl-3-isobutylxanthine，dexamethasone and insulin），treated by different concentrations of DZF from 2 d to 8 d of differentiation. The lipid accumulation of adipocyte was observed by BODIPY493/503 and DAPI double fluorescent staining. The intracellular triglyceride（TG） was detected by glycerol phosphate oxidase and peroxidase. RT-PCR was used to detect mRNA expression of CCAAT enhancer bind－ing protein-α（C/EBP-α），peroxisome proliferators-activated receptors-γ（PPAR-γ），acetyl-CoA carboxylase（ACC），fatty acid syn－thetase（FAS）. Western blot was used to detect protein expression of PPAR-γ and C/EBP-α. Results：DZF could inhibit adipocyte differentiation and reduce intracellular TG content in a dose-dependent manner. ACC mRNA expression was significantly down-regulated in large-dose DZF group than in control group（P<0.05）. FAS mRNA expression was significantly down-regulated in small，medium，large-dose DZF groups than in control group（P<0.01）. C/EBPα and PPAR-γ mRNA expression was significantly down-regulated in medium，large-dose DZF groups than in control group（P<0.01）. The result of Western blot was consistent with that of mRNA results. Conclusion：DZF could significantly inhibit the differentiation of adipocyte，the mechanisms might be related to the down-regulation of C/EBPα，PPAR-γ，ACC，FAS gene expression.