Abstract： Objective To study the significance on dynamic changes of serum vascular endothelial growth factor( VECF) and matrix metalloproteinase 9( MMP-9) in patients with acute cerebral infarction. Methods 123 patients with acute cerebral infarction were selected as research object, and they were the observation group, and 80 healthy peoples at the same time were selected as control group. Then the serum VEGF and MMP-9 in patients with acute cerebral infarction after pathogenesis at first,third,fifth,seventh and fourteenth day were detected,and the correction between the levels and infarct size,prognosis were studied. Results The serum VECF and MMP-9 of observation group compared with those of control group,the change showed increased first and decreased afterwards,but the levels were all higher than those of control group (P ＜ 0.01). There were correction between the levels and infarct size, prognosis.The serum VEGF[(369.3 ± 108.7,476.2 ± 118.4,551.5 ± 144.5,661.7 ± 164.6,437.6 ± 123.9)ng/L]and MMP-9[(333.8±101.4,459.7±119.9,370.3 ±119.5,320.5 ± 129.1,255.4 ± 101.6)ng/L] in poor prognosis patients after pathogenesis at first,third,fifth,seventh and fourteenth day were all higher than those of good prognosis patients ( P ＜0.01). Conclusion The serum VEGF and MMP-9 in patients with acute cerebral infarction showed dynamic change,and there was close relationship between the levels and infarct size.