Abstract: Objective To assess the application of MRI in clinical diagnosis of talus cartilage injury by comparing its findings and arthroscopic findings in talus cartilage injury. Methods Fifty-four patients（37 males and 17 females） with talus cartilage injury at an average age of 41 years（18-66 years）were included in this study.The patients underwent arthroscopy and routine ankle MRI for ankle cartilage injury.Cartilage injury was classified according to the Mintz classification method. Results The diagnostic rate of MRI was 42.9%,46.2%,93.1% and 100%,respectively,for stage 1,stage 2,stage 3 and stage 4 cartilage injury. Conclusion MRI is of important value for the clinical diagnosis of stages 3 and 4 ankle cartilage injury.Subchondral edema can predict cartilage injury,but is easy to lead to its incorrect staging.