@@ Introduction:Rectal cancer is one of the most commonly diagnosed cancers．Although the surgery resection with regional lymph node dissection is the mainstay treatment for rectal cancer,the outcome of stage Ⅱ/Ⅲ disease treated with surgery alone remains dismal。Which is mainly due to the local failure．Multidecipline treatment modalities in term of concurrent chemoradiotheapy have been used as an attempt to improve the treatment outcome of stage Ⅱ/Ⅲ rectal cancer,with increasing local control or survival rate．It is well accepted that local control of subclinical cancer foci with RT iS a function of the intensity of the radiation dose．Nevertheless,the radiation dose to the intra-abdominal structures is usually limited to 45-50Gy,because of the adjacent dose-limiting normal tissue structures,which might not be sufficient for eradicating subclinical residual disease．Furthermore,the addition of concurrent chemotherapy might further improve the treatment efficacy．The role of adjuvant chemoradiotherapy in patients with stage IIA (T3NO)rectal cancer is also controversial．