Abstract: In order to improve the lateral resolution and enhance the contrast of medical ultrasound imaging in the presence of phase aberration,a coherence-based correction method was proposed.The averaged coherence factor was proposed at first and used as a metric to evaluate phase aberration correction.By maximizing the averaged coherence factor,the time delay parameter of each channel was adjusted.Then a new set of coherence factors was calculated with the corrected data.And finally the corrected data was optimized by the coherence factors to form a B-mode image.The simulations on point targets and a cyst phantom showed that the proposed method outperformed the nearest-neighboring cross-correlation method and conventional coherence-weighting method,and the lateral resolution and contrast ratio was improved by approximately 0.24 mm and 18 dB respectively.The proposed method combined the advantages of phase error correction and coherence-weighting,which could improve imaging qualities effectively in medical ultrasound.