Aim: To observe the expression of insulin-like growth factor-1 receptor (IGF-1R) in the brain of diabetic mice and to provide theoretical basis for treatment of diabetic encephalopathy and Alzheimer disease (AD). Methods: Eighteen male Kunming mice were randomly divided into normal control group (C group), diabetic control group (DM group), and APP17 peptide-treated diabetic group (APP17 peptide + DM group). Diabetic mouse models were induced by strepozotocin injection, and β amyloid precursor protein 319-335 (APP17 peptide) was subcutaneously injected for the treatment. Brain tissue was taken 4 weeks later for IGF-1R immunohistochemical staining. Results: IGF-1R positive neurons were widely distributed in the cortex, hippocampus, and thalamus, etc. of the diabetic mice, and the cytoplasm was darkly stained. In contrast, positive cells in the hippocampaus were lightly stained in normal mice and the APP17 peptide-treated diabetic mice. The number of Hi-positive cells in DM, control and APP17 peptide + DM groups were 22.3 ± 1.7, 14.5 ± 1.4, and 15.2 ± 1.1 respectively under 10-power object lens. Conclusion: IGF-1R positive neurons abounds in some areas of diabetic mouse brain sad APP17 peptide can normalize their distribution and quantity.