Aim To investigate the relationships between C-reactive protein and carotid atherosclerosis and prognosis in patients with cerebral infarction. Methods 94 patients with first cerebral infarction were selected.The serum level of C-reactive protein was determined by immunonephelometric assay.The features of carotid atherosclerosis was assessed by carotid ultrasonography.The neurological deficit scores,mortality and disability rate were evaluated in patients with cerebral infarction. Results The carotid intima-medial thickness and the incidence of carotid unstable plaque in high C-reactive protein group were significantly higher than those of low C-reactive protein group in patients with cerebral infarction(P><0.05);The neurological deficit scores,mortality and disability rate in high C-reactive protein group were significantly higher than those of low C-reactive protein group in patients with cerebral infarction(P><0.01). Conclusion The serum level of C-reactive protein may reflect the character and plaque stability of carotid atherosclerosis in patients with cerebral infarction,which may bea prognostic marker in patients with cerebral infarction.