ObjectiveTo observe the changes of pancreatic islet cells in experimental macaques diabetes models. MethodsWe used streptozotocin (STZ) (30 mg/kg body weight, intravenously, 3 days) to five macaques. The animal was sacrificed when it was going to die. The changes of A, B, D, PP cells in the pancreatioc islets were observed with immunohistochemistry staining. Image analysis and statistical analysis of the histological changes were carried out. Results The quantity of A cells was significantly decreased than that in the control group (P<0.01). The positive immunohistochemical reaction of A cells was significantly increased compared with that of the control group (P<0.01). The positive PP cells were increased than that in the control group (P<0.05). There were no significant differences in D cells between the model and control groups. ConcusionThe number of pancreatic islet cells and changes of hormonal expression in experimental macaques models of diabetes mellitus is similar to that in diabetic human subjects.