Objective: To evaluate the influence of complete and incomplete pelvic autonomic nerve preservation (PANP) on urination function in patients with resection of rectal carcinoma. Methods: The changes of pre-and post-operative residual urine volume (RUV) in patient undergoing complete PANP (n = 15) and incomplete PANP (n = 17) were observed.Results: In fifteen cases with complete PANP, preoperative RUV was 4.09 ml, 14 days and 3 months after operation RUV were 8.00 ml and 7.02 ml (P ＞ 0.05). In seventeen cases with incomplete PANP, preoperative RUV was 3.90 mi, 14 days and 3months after operation RUV were 36.55 ml and 22.64 ml (P ＜ 0.001 ). Conclusion: Complete and incomplete pelvic autonomic preservation may affect urination function in patients with resection of rectal carcinoma and RUV is an effective indicator if the pelvic autonomic nerves are preserved completely.