To investigate the molecular mechanism of Huanglian Jiedu Decoction (HLJDD), a traditional Chinese compound herbal medicine, in treating type 2 diabetes mellitus (T2DM) by observing its effects on glucose transporter 4 (GLUT4) protein expression and translocation in adipose and skeletal muscle tissues of rats with T2DM.T2DM was induced in rats by intravenous injection of a small dose of streptozotocin (STZ, 30 mg/kg) plus high fat and high caloric laboratory chow. Then animals were divided into untreated group, aspirin-treated group and HLJDD-treated group. Normal rats fed with common chow were designated as normal control group. Ten weeks later, the oral glucose tolerance test (OGTT) was performed in all animals, and the changes of murine body weight, fasting blood glucose (FBG), fasting serum insulin (FINS) and the expression of GLUT4 protein in skeletal muscle and adipose tissues before and after insulin treatment were routinely determined.Compared with the untreated group, the result of OGTT of HLJDD-treated group was improved. The levels of the body weight and FBG were decreased, while the GLUT4 protein expression and translocation were elevated obviously.It is suggested by the present results that the therapeutic effects of HLJDD on T2DM might be related to its ability of increasing GLUT4 protein expression and translocation in adipose and skeletal muscle tissues of T2DM rats.