Number of patients: 458 cases Study design: patients will be randomly assigned into the total neoadjuvant treatment group (experimental group, TNT) and neoadjuvant concurrent chemotherapy group (control group, CRT) in the ratio of 1: 1. The patients of experimental group will be given 1 cycle of induction CAPOX (Oxaliplatin 130mg/m2 d1, Capecitabine 1000mg/m2, bid, d1-14) prior to radiotherapy. Then pelvic IMRT/VMAT (50-50.4Gy/25-28f) and two cycles of concurrent chemotherapy (Oxaliplatin 130mg/m2, d1, d 22, Capecitabine 825mg/m2, bid, 5d/w, 25-28d) are performed. And three cycles of consolidation chemotherapy (CAPOX) are delivered after concurrent chemoradiotherapy. Total mesorectal excision (TME) is performed after completion of the whole neoadjuvant treatment. The patients of control group will receive standard concurrent neoadjuvant chemoradiotherapy with capecitabine (825mg/m2, bid, 5d/w) followed by TME 6-8 weeks after the end of concurrent chemoradiotherapy. Then, patients are treated with another 6 cycles of CAPOX.