Objective To investigate the impacts of neoadjuvant chemotherapy on the expression of insulin-like growth factor-1 receptor (IGF-1R) and on operation procedure and the significance of prognosis. Methods The expression of IGF-1R in 40 patients with breast cancer before and after neoadjuvant chemotherapy was measured by immunohistochemistry. The diagnosis was proved by core biopsy. All the patients took the TAC chemotherapy regimen. Modified radical operation was performed after two chemotherapy cycles and the IGF-1R expression was measured again. The clinical effect of neoadjuvant chemotherapy was assessed according to WHO criterion by measuring the size of tumor by physical examination and B type ultrasound. Results After neoadjuvant chemotherapy the tumor size shrank in 29 patients, there was no CR (complete response) or PD (progressed disease) to be documented. IGF-1R expression could be downregulated in 25 patients. Conclusion Neoadjuvant chemotherapy can inhibit the tumor growth by downregulation of the expression of IGF-1R.