@@ Purpose To evaluate the performance of Breast Ultrasound Computer Decision Support (CDS) System based on a proposed China BIRADS standard.Methods A China specific BIRADS standard was proposed and a CDS system based on this BI-RADS standard was developed to help increase breast cancer screening in China. In this preliminary clinical study, we evaluated the CDS system on 150 breast lesions from the consecutive 130 patients which were enrolled and recorded in a database with reference to the proposed BI-RADS standard protocol. The breast US scans were performed for each patient prior to breast biopsy/surgery of the breast lesions. The descriptive lesion features were post processed by computer decision support (CDS) workstation to help differentiating malignancies from benign lesions. Besides, with the software developed, similar images from the different cases were also retrieved from the workstation pool for the doctor to review.