Objective To investigate the impact of conversion to open in laparoscopic rectal cancer radical resection (LRR) on postoperative recovery. Methods The data from Feb. 2003 to Feb. 2007 of 176 cases who were given LRR and 32 cases receiving conversion in LRR (CRR) were analyzed retrospectively, and were compared about operation time, hospitalization time, hospitalization expenses, intraoperative blood loss, recovery time of bowel movement and postoperative complications with 59 cases of open rectal cancer radical resection (ORR). Results There were no differences among LRR, CRR and ORR about operation time, hospitalization time, intraoperative blood loss and recovery time of bowel movement (Pgt;0.05). The hospitalization expenses of LRR and CRR were higher than that of ORR (P=0.001, P=0.001), there was no difference between CRR and LRR (P=0.843). But the postoperative complications rate of ORR was higher than those of LRR and CRR （P=0.023,P=0.004）. Conclusion Compared with ORR, LRR has relatively conversion rate, and then increases the hospitalization expenses.