Objective To observe the effects ofLiuwei Dihuang Decoction on cAMP and PDE3B in adipose tissues of rats with type 2 diabetes;To explore its mechanism.MethodsTotally 80 SD rats were randomly divided into two groups:control group and molding group. Rats in the molding group established the type 2 diabetic models by feeding high sugar and fat diet combined with intraperitoneal injection of Streptozotocin. The successful modeling rats were divided into model group, Rosiglitazone group, andLiuwei Dihuang Decoction group. Administration groups were given relevant medicine for gavage, while model group and blank group were given the same amount of normal saline for 30 days. FBG levels were detected, and cAMP and INS levels were detected by ELISA. The protein expressions of PDE3B in adipose tissues were determined by Western blot. The mRNA expressions of PDE3B in adipose tissues were detected by RT-PCR.Results Compared with the model group, the FBG and INS levels in type 2 diabetic rats were reduced in Rosiglitazone group andLiuwei DihuangDecoction group (P<0.05,P<0.01). InLiuwei Dihuang Decoction group, the protein and mRNA expressions of PDE3B in the adipose tissues were higher, and cAMP levels were lower than the model group (P<0.01).ConclusionLiuwei Dihuang Decoction can increase PDE3B expression, and decrease cAMP level, which may be one of the mechanisms for improving insulin resistance in type 2 diabetic rats.