Abstract: Neoadjuvant chemoradiotherapy combined with total mesorectal excision (TME) has become the standard treatment mode for locally advanced rectal cancer.Many researches have demonstrated that neoadjuvant chemoradiotherapy can improve pathologic complete response (ypCR) rate,anal sphincter operation rate and local control rate,but distant metastasis is still the main cause of death and no significant benefit is found for the overall survival rate.This article aims to investigate the influence of different radiotherapy segmentation methods and dose distributions,and different chemotherapy regimens on clinical outcomes of locally advanced rectal cancer.