Abstract: In synthetic transmit aperture medical ultrasound imaging field,a compressed sensing ultrasound imaging method based on the sparsity in frequency domain is presented in order to reduce the huge amount of data and huge amount of reciving channels.First,the sparsity in frequency domain was verified.Then the echo signal was compressively sampled in time-spatial domain based on compressive sensing and the echo signal was reconstructed by solving an optimization problem.Finally the image was made by using synthetic transmit aperture approach.The experiments based on point target and fetus target were used to verify the proposed method.The RMS error,resolution and image quality of reconstructed image and those of original image were compared and analyzed.The results showed that only 30%amount of data and 50%of receiving channels were used to implement ultrasound imaging without reducing the quality of image in the experiment.The amount of data and the complexity of system are reduced greatly by the proposed method based on compressed sensing method.