Abstract: Objective To observe the changes of peripheral blood endothelial progenitor cells (EPCs) in patients with acute cerebral infarction (ACI). To investigate the predictive value of EPCs in the neurologic impairment symptoms of acute cerebral infarction. Methods Consecutive 72 patients with acute ischemic stroke within 24 hours were enrolled in the study, and all patients were diagnosed acute ischemic stroke for the first time. At the same time to choose our stroke screening outpatient 50 cases as control group. To within 1 week of the highest of the National Institute of Health stroke scale (NIHSS) scores as the evaluation criteria for the severity of the neurologic impairment symptoms of acute cerebral infarction. As CD133⁺KDR⁺ cells as a sign of EPCs, using flow cytometry in patients with acute cerebral infarction incidence 1, 5, 10 days the number of peripheral blood EPCs. Results In patients with acute cerebral infarction 1 d, 5 d, 10 d number of EPCs in 1 d reduce 5 d increased 10 d downward trend, and were significantly lower than the control group (all P < 0. 05). Severe group 1 d, 5 d, 10 d number of EPCs were lower than that of mild group, and a statistically significant differences (all P < 0. 05). Cerebral infarction in patients with acute phase NIHSS score and the onset of EPCs negatively correlated with the number 1 d, 5 d, 10 d (r₁=-0. 762, r₅=-0. 622, r₁₀=-0. 414, all P < 0. 05). Conclusion Baseline level of EPCs was significantly lower in patients with ACI than control group, EPCs may be an risk factor for acute cerebral infarction. Cerebral infarction in patients with acute phase, the lower the number of EPCs and the heavier of the neurologic impairment symptoms. EPCs in patients with cerebral infarction in acute stage of the neurologic impairment symptoms assessment has a guiding significance.