Objective To study the value of color Doppler ultrasonography and thermography in the diagnosis of breast cancer.Methods Three hundred cases of breast mass were divided into two groups,each group composed of 150 cases.GroupⅠwas examined with color Doppler ultrasonography,groupⅡwas examined with color Doppler ultrasonography and thermography synchronously.Results The average pixel density in color blood flow of breast cancer was 22%,while the density of benign masses was 12%.The average temperature difference of breast cancer with thermography was 2.1 ℃,while that of benign mass was 1.5 ℃.The statistical difference existed between the benign mass and the breast cancer (P