Objective    To investigate the value of color Doppler flow imaging in evaluation of the hip joints’ blood flow in avascular necrosis of femoral head (ANFH).      Methods    Eighteen adult ANFH models were made in New Zealand rabbits by intramuscular injecting 8 mg/kg prednisolone acetate twice per week for 4 weeks followed by once per week for 6 weeks. Color Doppler flow imaging (15L8w

10.0 to 14.0 MHz) were carried out to examine the hip joints’ blood supply before the injection

and 4 and 10 weeks after the injection. Digital radiography and magnetic resonance imaging were performed

and serum total cholesterol and triglyceride levels were measured at the same time points. HE staining was used to study the morphological change of the hip joints.     Results    The flow velocity of the small vessel in the hip joints at 4 weeks and 10 weeks after the injection were significantly lower than before the injection (P0.05)

and artery resistance index (RI) was still increased (P0.01). There was no obvious changes in the X-ray film after injection

but changes were found in MR image in 10 weeks after the injection. HE staining showed typical avascular necrosis in the femoral head.     Conclusion    Ultrasonography can evaluate the hip joints’ blood supply of avascular necrosis of the femoral head.