OBJECTIVE: The purpose of this study is the evaluate the diagnostic accuracy of MRI, frequent location of injury site and injury type in meniscal injury, retrospective review of false positive cases. METHOD: From September 193 to January 1997 in our hospital, we analyzed a hundred cases of meniscal injury suggested by MRI. And we tried to correct operatively in meniscal injury by arthroscopic or open method of operation. RESULT: 1)Diagnostic accuracy of MRI was 90% 2)Most common site of meniscal injury was medial meniscus posterior horn(54.4%). 3)Most common injury type was Bucket handle tearing(34.4%). 4)Cause of pitfall in false positive case was most common popliteal tendon sheath(30%). CONCLUSION: MRI was effective method on diagnosis of meniscus injury and most common injury was medial meniscus posterior horn, And diagnostic fault was caused by popliteal tendon sheath, lateral inferior genicular artery, truncation artifect, meniscofemoral ligament, transverse geniculate ligament.