【Abstract】Objective To access the efficacy and safety of modified retroperitoneal laparoscopic pyeloplasty of the treatment for ureteropelvic junction obstruction（UPJO）. Methods 62 patients with UPJO from March 2013 to May 2015 in our hospital were collected in department of urology, and divided into observation group and control group by the random number table method, 31 cases in each group. The observation group was treated with modified laparoscopic surgery, while the control group was treated with standard laparoscopic surgery. The perioperative period data, complications, patient satisfaction and followup outcomes of two groups were observed and compared. Results The UPJO operation was successful in 62 cases. There was no significant difference in operation time, blood loss, complication rate and exhaust time between the two groups. The analgesic dosage in the non modified group was higher than that in the modified group. The number of days in hospital was better than that in the modified group. After 1 years, the AP of the two groups were significantly lower than those before the operation, and the glomerular filtration rate was significantly higher than that before operation (P＜0.05). There is no difference between the two groups. Conclusion Modified transabdominal laparoscopic surgery for the treatment of UPJO is accurate, safe, less trauma, less pain and has short recovery time.