The imaging diagnostic techniques include X-ray plain film,ultrasound,CT,MRI and radionuclide imaging.X-ray plain film is less sensitive to early acute osteomyelitis.Ultrasound can detect abscesses in the soft tissues and subperiosteal space earlier,but there are variations in image quality based on the different operators’ levels of proficiency.High-resolution CT can find minimal lesions on bone,but it has a low sensitivity to predict acute osteomyelitis.MRI is superior to other imaging techniques at visualizing bone marrow lesions,but it is less sensitive in detecting sequestrum and calcification than CT.A variety of radionuclide imaging agents have been used in the early diagnosis of acute osteomyelitis in order to find a more sensitive and specific imaging technique.In this paper,different imaging diagnostic techniques of acute osteomyelitis are reviewed.