Abstract: To study the effect of the crude polysaccharides from Poria cocos (PCCP) on mRNA expression of adipogenic factors during 3T3-L1 preadipocyte differentiation. 3T3-L1 preadipocytes were induced to differentiate with MDI (3-isobutyl-1-Methylxanthine, Dexamethasone and Insulin) induction media contained PCCP (50 μg mL-1) and cultured for 8 days. The extent of the differentiation was assessed by Nile Red staining and GPDH activity. In addition, researchers used real-time quantitative PCR to analyzed the expression of genes related to adipocyte differentiation. The results showed that treatment of differentiating 3T3-L1 preadipocytes with PCCP (50 μg mL-1) resulted in an increase in the expression of the adipocyte genes such as Fatty Acid System Synthase (FAS), adipocyte fatty acid binding Protein (aP2), insulin-responsive Glucose Transporter (GLUT4) and transcriptional factor genes such as CCAAT/Enhancer Binding Protein α (C/EBPα), peoxisome Proliferator-Activated Receptor gamma (PPARγ) and Sterol Regulatory Element-Binding Protein 1c (SREBP-1c) to some degree. Overall, the data suggested that there was the tendency of increasing the expression of genes related to adipocyte differentiation in PCCP treated cells.