Aim To investigate the relation between Lp-PLA2 levels and degree of carotid atherosclerosis,and meanwhile to explore the relation between lipids、hs-CRP and Lp-PLA2 levels. Methods 138 cases(70 male cases and 68 female cases) were collected and their bilateral carotid arteries were examined by color Doppler ultrasound.According to the results of color Doppler ultrasound,the 138 cases were divided to four groups:30 cases with normal carotid arteries;38 cases with intima-media incrassation of carotid arteries;and 70 cases with plaque.The Lp-PLA2 concentration of limosis blood serum was determined by ELISA method.hs-CRP concentration and total cholesterol(TC),triglycerides(TG),low density lipoprotein(LDL) were determined as well. Results The concentration of TC,hs-CRP,and Lp-PLA2 were lower in the group with normal carotid arteries and intima-media incrassation of carotid arteries than those in the groups with plaque,and there were significant differences(P<0.05).No significant difference was found in TG and LDL among the three groups(P>0.05). The concentration of Lp-PLA2 and TC,LDL,hs-CRP are of significantly positive correlation(r=0.279,0.187,0.176,P=0.001,0.028,0.039).No significant difference was found between Lp-PLA2 and TG(r=0.100,P=0.244). Conclusion The Lp-PLA2 was associated with CAS degree as a factor of promoting atherosclerosis,especially of the negativity or positivity of the exisitence of plaque.The mechanism may be related to lipids and inflammation.