Objective To investigate the procedure and efficacy of medial patellofemoral ligament (MPFL) reconstruction assisted with arthroscopy for recurrent patellar dislocation in adolescents.Methods From March 2012 to March 2017,15 adolescents suffered with recurrent patellar dislocation,who underwent MPFL reconstruction operation,were all adopted with autograft semitendinosus.The patellar side used the modified bone tunnels and the minimally invasive percutaneous grafts through bone tunnels,and then fixed in the femoral tunnel with absorbable interference screw.Follow-up included complications,subjective feeling,patellar apprehension test,recurrent dislocation.Knee function was evaluated by the Kujala score and Lysholm score.Results 15 patients were followed up for at least 12 months.All patients were satisfied with the treatment.No recurrent dislocation occurred.All the patients showed negative apprehension test.The Kujala score was improved from 53.2 ±5.27 (preoperative) to 93.0 ±4.13 (postoperative),with significant difference (t =21.84,P ＜ 0.05);the Lysholm score was improved from 54.5 ± 6.24 to 91.2 ±4.72,with significant difference (t =19.37,P ＜ 0.05).Conclusions MPFL reconstruction assisted with arthroscopy is an effective surgical procedure for adolescent patients wih recurrent patellar dislocation,which can improve the knee function with little trauma and complications.