Objective:This study aims to review the magnetic resonance imaging(MRI)features of normal grafts at different stages of signal characteristics and complications after anterior cruciate ligament reconstruction(ACLR). Methods:The imaging data of 299 patients who underwent MRI for reexamination after the ACLR at the First Affiliated Hospital of Nanjing Medical University from January 2012 to March 2023 were reviewed,and were classified according to the different manifestations of graft complications on MRI. Their signal on T1WI and T2WI was described and combined with their clinical symptoms. Results:In 299 patients,signal was highest at 4-6 months postoperatively. Post-transplantation complications were observed in 66(22.07%),of which 5(1.67%)had an anterior displacement of the tibial tunnel ,and 1(0.33%)had a slightly posterior position of the tibial tunnel. Cyclops lesion was seen in 16(5.35%),re-rupture of the graft occurred in 10(3.34%),and 1(0.33%)had a postoperative infection. Cystic signal in the tunnel were present in 33(11.04%)at various times postoperatively. There are 2 patients who underlying anterior displacement of the tibial tunnel had both re-rupture and Cyclops lesion of the graft. Conclusion:MRI plays an important role as a major tool for postoperative follow-up of patients after ACLR. It can clearly reflect the changes of the graft at different stages and the manifestation of complications,providing early detection and warning,so that clinicians can take early interventions to improve the quality of life for patients after surgery.