【Abstract】 Objective To investigate the factors affecting the stability of carotid atherosclerosis plaque in patients with acute cerebral infarction. Methods The clinical data of 128 patients with acute cerebral infarction admitted in our hospital from May 2012 to May 2017 were retrospectively analyzed. All patients underwent carotid artery color Doppler ultrasound and regular examinations. The formation, stability and related clinical indicators of carotid atherosclerosis plaques were analyzed then. Results The carotid artery ultrasonography showed that all patients had carotid atherosclerotic plaques, of which plaques were stable in 70 cases (5469%), and plaques were unstable in 58 cases (4531%). The levels of TC, TG, FPG and UA between the two groups had no difference (P＞005). However, the levels of Hcy, CyC, CRP, FIB, LDL, IL6 and ICAM1 in patients with unstable plaque were significantly higher than those with stable plaque (P＜005). Unconditional univariate Logistic regression model analysis showed that the rising proportions of Hcy, CyC, CRP, FIB, LDL, IL6 and ICAM1 in patients with unstable plaque were significantly higher than those in patients with stable plaque (P＜005). Unconditional multivariate Logistic regression model analysis showed that elevated levels of Hcy, CyC, CRP, and FIB were independent risk factors for carotid atherosclerotic plaque instability in patients with acute cerebral infarction (P＜005). Conclusion Most acute cerebral infarction have unstable carotid atherosclerotic plaques, which is related with the elevated levels of Hcy, CyC, CRP, and FIB.