Objective To study the level changes and correlation of homocysteine (Hcy) ,high-sensitivity C-reactive protein(hs-CRP) ,cystatin C(Cys-C) and plasma fibrinogen(Fib) in the patients with acute cerebral infarction (ACI) .Methods The fasting blood samples were collected from 178 cases of ACI(ACI group) and 93 healthy individuals blood samples (control group) .The lev-els of serum Hcy ,hs-CRP and Cys-C were detected by the BECKMAN AU-680 fully automatic biochemical analyzer and plasma Fib was determined by the RAC-100 fully automatic coagulometer .Results The levels of serum Hcy ,hs-CRP ,Cys-C and plasma Fib in the ACI group were significantly increased compared with the control group (P<0 .05) .There was significantly positive correlation between Hcy with hs-CRP and Cys-C in the ACI group(r=0 .326 ,0 .361 ,P<0 .05) ,but there was no significant correlation be-tween Hcy and Fib ;there was significantly positive correlation between hs-CRP with Cys-C and Fib(r=0 .365 ,0 .421 ,P<0 .05);the same significant positive correlation also existed between Cys-C and Fib (r=0 .447 ,P<0 .05) .The positive rate of the joint de-tection of Hcy ,hs-CRP ,Cys-C and Fib was 93 .8 % ,which was obviously higher than that of the single indicator detection (P<0 .05) .Conclusion Cys-C ,hs-CRP ,Fib and Hcy participate in the occurrence and development process of ACI ,their joint detection has the important clinical significance for the prevention ,early diagnosis and treatment of ACI .