To evaluate the role of MR in the examination of Legg-Calv -Perthes(LCP) disease, we retrospectively analysed the signal intensity of the osseous lesion, thickness of the articlar cartilage, change of surrounding soft tissue, joint effusion and femoral head containment in 32cases of LCP diseases in 27 patients. The bony lesion was limited witin the epiphysis in 19cases(59%) and extended to the Physis and metaphysis in 13cases(41%). The epiphyseal lesion showed homogeneous(26/32) or heterogenous(6/32) low signal intensity(SI) on T-1 weighted images (T1WI), and homogeneous(16/28) or heterogeneous(12/28) low SI on T-2 weighted images (T2WI). The metaphyseal lesion showed low SI (13/13) on T1WI, and low (9/11) or iso(3/11) SI on T2WI. Associated metaphyseal cyst showed low SI on T1WI and high SI on T2WI. An althought physeal involvement(13/32) was indistinct, the lesion showed increased SI on both T1 and T2WI. Thickening of articular cartilage(32/32). swelling of the ligamentum te es(7/32). synovial hypertrophy (7/32) and joint effsion(27/32) were demonstrated. Lateral subluxation of the femoral head on coronal image indicated incongruity of the femoral head in 25cases(78%). We conclude that MR is an useful tool for the diagnosis as well as treatment planning in LCP disease.