Objective: To investigate the tracing fect of new nano-carbon (Kanalin) on the pelvic lymph nodes of the patents with bladder cancer during the laparoscopic radcal cystectomy (RC), and to explain the signcance of its applicaton in the precision surgical treatment. Methods: A total of 44 patents with bladder cancer who underwent RC were divded into tracer group (n=22) and control group (n=22) according to whether Kanalin was used before operaton or not. The laparoscopic RC combined with standard pelvc lymph node dissecon (LND) was performed in the patents in two groups. The effectiveness evaluaton indexes and safety evaluaton indexes of the patents in two groups were collected and compared. The efectiveness evaluaton indexes included black staining situaton of lymph nodes during operaon, the number of detected lymph nodes, the black staining rate of lymph nodes, the number of positive lymph nodes, and operaton time. The safety evaluaton indexes included the blood loss and the indences of perioperative complicatons. Results: The black sainng fect of lymph nodes of the patents in tracer group was definite and there were no tracer-related sde effects and complicatons during the perioperative period. Compared with control group, the clearance rate and detecon rate of lymph nodes of the patents in tracer group were increased (P<0. 01). The black staning rate of lymph nodes of each case was higher than 50%, even up to 85%. There were no significant dfferences in the number of positive lymph nodes, the operaon time, the blood loss and the perioperative complicaton rates of the patents between two groups (P> 0. 05). Conclusion: During the laparoscopic RC, the applicaton of Kanalin for pelvic lymph node tracng is safe, without toxic and side effects; Kanalin is helpful for ncreasing the intraoperative clearance rates and postoperative pathological detecon rates of lymph nodes.