Objective To study the influence of dl-3n-butyphthalide on serum C-reactive protein(CRP)level in patients with acute cerebral infarction.Methods A total of 68 patients with acute cerebral infarction were chosen and divided into two groups randomly.Both the groups were treated with normal method and the treatment group was given dl-3n-butyphthalide 200 mg,tid.Serum CRP levels in the two groups were measured by immunoturbidimetry within 24 h after final diagnosis and at two weeks after treatment.Results Serum CRP levels all increased in the patients.After treatment for two weeks the level decreased obviously in treatment group.The difference was significant compared with control group.Conclusion The dl-3n-butyphthalide can markedly decrease the serum CRP level in acute cerebral infarction patients and has important significance for the pathogenetic condition change and prognosis of cerebral infarction.