摘要Objective: To investigate the effect of Quyu Xiaoban Capsule (祛瘀消斑, QYXB) on the regressive treatment of atherosclerosis (AS) with acoustic densitometry (AD) technique. Methods: Eighty patients with AS were randomly divided into two groups, trial group was treated with QYXB and conventional medicine, and control group was treated with conventional medicine alone. Normal arterial wall and different types of atherosclerotic plaques were detected with AD technique before treatment and 10 months later. Resuits: The corrected averages in intimal echo intensity (AIIc%) were elevated in both groups but without significant difference, AIIc% of fatty plaques were increased in both groups and the value after treatment was significantly higher than that of pre-treatment in the trial group (68.12±5.54 vs 61.43±5.37, P＜0.05).The increment rate of AIIc% in trial group was significantly higher than that in control group (10.9±5.1% vs2.5±5.5%, P＜0.05). Conclusion: QYXB can stabilize the atherosclerotic plaque by increasing its acoustic density. Acoustic densitometry technique can differentiate the different histological plaques and monitor the histological changes of plaques during treatment.