Objective To explore the changes of the expression of islet amylodi polypeptide (IAPP) and somatostatin(SS) of islet in type 1 diabetes mice, and the mechanism of the expression changes. Methods We established the diabetes model in C57BL/6J mice by low-dose streptozotocin (STZ) injection. The excisions of the pancreas tails removed on the 3th, 7th, 10th, 14th, 21th and 28th day. Tissues were assessed by immunohistochemical SABC, immunofluorescence in the study. Results 1. Numerical density on area (N_A) of IAPP positive cells in experimental group (EG) decreased since the 3th day, but average absorbance increased since the 7th day. 2. N_A of SS-IR cells in EG increased since the 3th day, and average absorbance increased since the 7th day. 3.The results of immunofluorescence double staining showed that, IAPP and SS could coexpression in part of cells in islets. Conclusion The number of IAPP positive cells in type 1 diabetes is decreased, but the immunoreaction increased. Immunoreaction and number of SS positive cells increase. Both of them are involved in the pathogenesis of type 1 diabetes.