We evalusted the magnetic resonance imaging (MRI) findings of the femoral heads in 20 normal and 45 abnormal pateints. The bone marrow in the healthy adults consisted of a combination of hematopoietic and fatty narrow, which showed age-related dirtribation, that is the component of fatty marrow was increased and the marrow vascularity was dereased with age. Avascular necrosis (AVN) showed a decreased bone marrow signal within an normal appearing femoral head on T1 and T2-weighted images. In addition, we could see inhomogenous low signal intensity (31 cases), a ring of low intensity (4 cases). MRI findings were abnormal in 10 cases with normal radiographic findiags as well as in all the cases with abnormal ones. In conclusion, MRI should be the choice of the imaging modality for the evaluation of early bone marrow chages of AVN.