Background Tacrolimus,a calcineurin inhibitor,is recommended by the recent guidelines from the Kidney Disease Improving Global Outcomes Group as the first-line treatment for steroid-resistant nephrotic syndrome (SRNS),but its clinical application in China is still limited.We investigated the efficacy and safety of tacrolimus combined with low-dose corticosteroids in a population of Chinese children with SRNS.Methods In this prospective non-randomized,non-controlled study,Chinese children with SRNS who failed the previous full-dose prednisone treatment were given tacrolimus (0.1 mg/kg/day) and low-dose prednisone (0.25-0.50 mg/kg/day).We compared the overall remission rate (ORR) and adverse events in the follow-up period with this therapeutic regimen.Results A total of 76 children were enrolled into the study with an average follow-up period of 18 ± 6 months (maximum 36 months).ORR achieved by the first,third,and sixth months was 94.7％,94.7％,and 96.0％,respectively.All patients who attained an initial tacrolimus trough concentration (FK506C0)＞ 6 ng/mL (60.3％) achieved remission.The relative risk of relapse at FK506C0 ＜ 3 ng/mL compared to 3-6 ng/mL,6-9 ng/mL,and 9-12 ng/mL was 2.3,3.2,and 16.9,respectively.During the follow-up period,adverse effects that had been previously reported were rare.Conclusions Combination of tacrolimus and low-dose prednisone was safe and effective for the treatment of children with SRNS,with high remission rates observed as early as the first month.Relapses were infrequent,but tended to increase significantly with decreases in FK506C0.