To investigate the effect of Astragalus polysaccharide (APS) treatment on type 2 diabetes mellitus (T2DM) rats and the GLUT4 expression in myocardium. 40 Wistar (male) rats were randomly divided into 4 groups: the control group, T2DM group (high-heat diet+ 35 mg· kg~(-1), a low dose of streptozotocin by end intravenous injection), APS group (control+ APS) and APS+ T2DM group (APS 400 mg· kg~(-1)· d~(-1) by irritating the stomach with the solution). After treatment for 5 weeks, the levels of serum glucose and insulin were assayed, and the expression of GLUT4 protein was assessed by immune fluorescence. The levels of glucose and body weight in T2DM group were increased (P< 0.01) and the levels of the GLUT4 expression in their cardiac tissues were lowered (P< 0.01) while the change of serum insulin levels had no statistics difference (P> 0.05) compared with the others respectively. The levels of glucose in APS+ T2DM group were higher than those of theh control group. Each index between APS and control group has no statistics difference (P> 0.05). APS can reduce the levels of glucose in T2DM rats and improve the insulin resistance of cardiac tissue, and this protective mechanism may be relative to the enhanced GLUT4 expression in type 2 diabetic myocardium.