We studied 90 patients(179 femoral heads) with avascular necrosis of femoral head, who had been performed X-ray, bone scan and MRI to copare of the findings of AVN on bone scan between each other, retrospectively. The patients were 82 males and 9 females, their mean age was 45 years. Radiographic stages were classifted by Steinberg modification, radionuclide stages were classified as followed; stage o(or type 0): noraml, stage 1: faint ring like uptake around the femoral head, stage 2: intense ring like uptake, stage 3: irregular increased uptake with central photon defect, stage 4: intense diffuse increased uptake at fem- oral head and stage 5: hip joint deformity with relatively mild increased uptake. The findings of MRI were classified according to extent, location, early or advanced lesion, signal int,ensity of the lesion and joint effusion. 156(87%) of 179 femoral heads had avascular necrosis, 68(75.5%) of 90 patients had bilateral AVN, 36 femoral heads had early stage and 120 had advanced stage. The detection rate of AVN by X-ray and bone scan were 85%(134), 91.6% (143), respectively. Early AVN with atypical types of bone scan showed larger extent, moderate to large amount of joint effusion, soft tissue hypertrophy within joint, and secondary degenerative changes. Bone scan had relatively high detection rate in the diagnosis of AVN of femoral head, and demonstrated various t.ypes depending on the disease stage.