Objective To investigate the prevalence and charateristics of carotid atherosclerosis among healthy middle-aged people of community. Methods Totally 1930 subjects aged 50 years and above were selected randomly from 10027 participants recruited during Phase 3 of the Guangzhou Biobank Cohort Study (GBCS).Common carotid artery intima-media thickness (CCA-IMT) and carotid plaques (CP) were measured by B-mode ultrasonography using ALT HDI 3000 mainframe with a high-resolution. Results The prevalences of CCA-IMT and CP in men were higher than women [41.5％(400/963)vs.16.2 (157/967),34.1％ (328/967) vs.13.8％ (133/967),both P＜0.001].The prevalence of CCA-1MT was higher with age increasing in either men or women in groups of 50-yrs,60-yrs and 70-79 yrs (all P＜0.001).The most of CP was cankerous spot (37.8％),secondly hard spot (24.9％),soft spot (22.1％) and the prevalence of flat spot was lowest (15.2％).The number of CP was not significantly different between the left and right side (51.0％ and 49.0％).The most common location of CP was bifurcations of carotid arteries (61.7 ％),next the common carotid artery (21.0％) and internal carotid artery (ICA) was lowest (17.3 ％).The prevalence of CP was 44.4％ (83/87) in women aged 50- yrs,it was higher than that in men 20.9％ (108/517).However,the prevalence of CP was 79.1％ (409/517) in men aged more than 60 yrs,higher than that in women (55.6％). Conclusions The carotid atherosclerosis is commonly encountered disease in the male elderly,and the most of CP was cankerous spot in bifurcations of carotid arteries