OBJECTIVE: To explore the effects of berberine and insulin on adiponectin mRNA expression in 3T3-L1 adipocyte. METHOD: The 3T3-L1 adipocyte was treated with berberine and insulin for 48 hours, the level of adiponectin mRNA in 3T3-L1 adipocyte expression was determined with semiquantity RT-PCR using beta-actin as internal reference. RESULT: The level of adiponetin mRNA in 3T3-L1 adipocyte was increased after treated with berberine only (P < 0.05), the effect of berberine was inhibited by high concentration insulin (P < 0.05). CONCLUSION: In vitro, berberine increases the expression of adiponectin in 3T3-L1 adipocyte, insulin inhibits the effect of berberine.