Objective:To study the operating law of different sets of instruments in laparoendoscopic single-site surgery. Methods:Seven laparoscopic-experienced participants were arranged to perform two basic tasks (peg transferring and pattern cutting) using conventional instruments,double-curved instruments and articulating instruments randomly in a modified simulator for 5 days (each instrument was trained for 2 times a day),and finally a test of the tasks were performed by each of the participants. In addition,the instruments of National Aeronautics and Space Administration Task Load Index (NASA-TLX) were completed to investigate the workload for the participants. Results:The task scores of double-curved instruments were worse than the other two sets of instruments in the task of peg transferring (double-curved instruments 239.4 ± 11.9 vs. conventional instruments 251.0 ± 7.4 vs. articulating instruments 254.4 ± 4.6,P < 0.05). The articulating instruments got the best performance in pattern cutting (conventional instruments 304.0 ± 41.4 vs. double-curved instruments 362.6 ± 33.2 vs. articulating instruments 405.4 ± 21.9,P < 0.05). The workload measured by NASA-TLX tool demonstrated that double-curved instruments and articulating instruments had a heavier workload compared with conventional instruments in mental demand,physical demand and effort. There was no significant difference on temporal demand and performance. Participants were more self-confident using articulating instruments compared with the other two sets of instruments. Conclusion:Articulating instruments is more effective and favorable than conventional and double-curved devices for laparoscopic-experienced surgeons in the laboratory setting of laparoendoscopic single-site surgery.