Aim To investigate the change of interleukin-10(IL-10)level in patients with acute cerebral infarction(ACI)and its relation with the volume of infarction.Methods Patients with ACI were divided into three groups of the large,the midst and the small by the volume of infarction and made group comparison.The serum level of IL-10 was measured by enzyme linked immunosorbent assay(ELISA)at 1,3,7 and 14 days after cerebral infarction.Results Compared with control group,the serum level of IL-10 was not increased at 1st day after cerebral infarction,but increased at 3th and 7th day after cerebral infarction,especially in the large size of infarction group,with a maximum increase at 7th day,the midst and the small were lower.The serum level of IL-10 reached the baseline at 14th day.Conclusion The serum level of IL-10 is significantly increased from 3 to 7 days after cerebral infarction.