Objective To study the relationship between high-sensitivity C-reactive protein level and carotid plaque in patients with acute cerebral infarction. Methods 73 patients with acute cerebral infarction were selected as research subject,then all the patients were tested with color doppler ultrasound.The patients were divided into unstable plaque group(A group)23 cases,stable plaque group(B group)25 cases and no plaque group(C group)25 cases,at the same time,25 healthy persons were selected as the control group(D group).The high-sensitivity C-reactive protein level and carotid plaque of the four groups were studied. Results The rate of carotid plaque with acute cerebral infarction was higher than that of healthy person(all P＜0.05),and the high-sensitivity C-reactive protein level of D group was lower than that of A group,B group and C group,and the level of A group was higher than that of B group and C group(all P＜0.05). Conclusion The detection rate of carotid plaque and high-sensitivity C-reactive protein level with acute cerebral infarction were both higher than those of healthy persons.It indicated there was cloce relationship between high-sensitivity C-reactive protein level and carotid plaque.