Abstract: Objective To compare the particle or mass concentration of lipoprotein（a） and the character of atherosclerotic plaques and to analysis the effect of lipoprotein（a） on the formation of atherosclerotic plaques. Methods A retrospective study of total 91 patients who underwent computed tomography angiography （CTA） in our hospital from January 2015 to August 2016 were performed. Based on the result of CTA,those patients were divided into two groups,the control group and the coronary atherosclerotic heart disease （CAHD） group. The particle and mass concentration of lipoprotein（a） were compared between two groups. Additionally,according to the character of atherosclerotic plaques,patients in the CAHD group were further divided into three group,comprised of the soft plaque group,the mixed plaque group and the calcific plaque group. The particle and mass concentration of lipoprotein（a） in these three groups were also compared. The correlation between particle concentration and mass concentration of lipoprotein（a） was analyzed. Results The particle and mass concentration of lipoprotein（a） were significantly higher in the CAHD group compared to the control group （t=3.4707,P=0.0008 and t=3.1524,P=0.0022）. The obvious difference of particle and mass concentration of lipoprotein（a） was observed in three groups of different character of atherosclerotic plaques （F=55.175,P<0.0001 and F=6.124,P=0.004）. Among those three groups,patients in the calcific plaque group had the highest level of particle and mass concentration of lipoprotein（a） （P<0.05）. The correlation between the particle concentration and the mass concentration of lipoprotein（a） was seen （r=0.5646,P<0.0001）. Conclusion Elevated level of lipoprotein（a） could be seen in CAHD patients,and the level of lipoprotein（a） has relationship with the character of atherosclerotic plaques. Lipoprotein（a） could play different roles in the formation of different kind of atherosclerotic plaques.

Key words: Lipoprotein（a） particle concentration, Mass concentration, Coronary atherosclerosis, Character of atherosclerotic plaques