Objective:To investigate the diagnostic value of cryptorchidism by color Doppler ultrasound.Methods:Fifty-four cases of cryptorchidism in the last 3 years were determined in location,size,interior structure and blood flow by color Doppler ultrasound prior to operation.Results:The diagnostic accuracy rate was 83.3%.Conclusions: color Doppler ultrasound plays an important role in the diagnosis of cryptorchidism.