Abstract: Objectives To compare the influence of transversus abdominis plane (TAP) on intraoperative and postoperative analgesia at different time points in the abdomen laparoscopy operations. Methods 120 patients undergoing abdomen laparoscopy under general anesthesia were allocated randomly to receive TAP block with 0.4% ropivacaine 40ml, either pre-incisional (group A), or at the end of surgery (group F) or sham block (saline, group C). Hemodynamic parameters during skin incision，peri-operative analgesic requirements, the amount of postoperative fentanyl and the side effects were recorded. Pain was evaluated postoperatively while coughing and at rest by visual analogue scale at 3,6,12,24,30,48h after operation. Results Hemodynamic parameters among three groups were comparable. The usage of Remifentanyl in group A was lower than that in group F and C (P<0.05). Fentanyl requirement and pain scores were lower in group A and F than in group C at 3,6,12,24h after operation (P<0.05), while those were lower in group F than in group A and C at 30h postoperatively (P<0.05). Compared with group A, Fentanyl requirement in group F was higher at 3h postoperatively（P<0.05）. Incidence of postoperative nausea and vomiting were no significant different. Conclusion Our results suggest that TAP block seems to be related with the acting time of local analgesic and no significant difference on analgesic effects of TAP either pre-incisional TAP or at the end of operation.