Objective To study the mechanism of urinary Kallidinogenase combined with aspirin in treat-ment of acute cerebral infarction. Methods Eighty-six patients with acute cerebral infarction were randomly divid-ed into the observation group(n=43)and the control group(n=43).The observation group was treated with uri-nary Kallidinogenase combined with aspirin,while the control group was treated only with aspirin.Two weeks after the treatment,variables of hemorheology,serum Hcy,hs-CRP,VEGF,IL-6,Cys-C,neurological deficit(NI-HSS)and daily living ability(ADL)were compared between the two groups. Results After treatment,the serum Hcy,hs-CRP,VEGF,Cys-C,IL-6 levels,the NIHSS and ADL in the observation group were significantly better improved than those of the control group(P<0.05).The clinical efficacy in the observation group was significantly higher than that of the control group[95.35%(41/43)vs 74.42%(32/43)](P<0.05).Conclusion Urinary Kal-lidinogenase combined with aspirin is more effective in the treatment of acute cerebral infarction. The mechanism may be related to the early improvements of serum Hcy,hs-CRP,VEGF,Cys-C and IL-6 expression.