Objective To investigate the preventive effect of potassium citrate sustained-release tablets on the formation of adherent stone in ureteral stent-graft after retrograde intrarenal surgery. Methods Patients with upper urinary tract calculi after retrograde intrarenal surgery and without stasis confirmed by color ultrasound were randomly divided into test group and control group. Patients in test group were given potassium citrate sustained release tablets 3 times(1.08 grams each time)orally but those in the control group did not take the drug. Two groups of patients received conventional health education and diet guidance. The formation of adherent stone in ureteral stent-graft during surgical removal of ureteral stent and the adverse reactions during taking the medication 3,6 and 16 weeks after the surgery were compared. Results There were few cases of adherent stone formed 3 weeks after the operation,which can not be statistically analyzed. The incidence of adnexal calculus in the test group 6 and 16 weeks after the operation was significantly lower than that of the control group,which was statistically significant.No serious adverse reactions and complications occurred in the test group during the medication-taking. Conclusions Potassium citrate sustained-release tablet is safe and effective for preventing the formation of adher-ent stone in ureteral stent-graft after upper urinary tract calculi retrograde intrarenal surgery.