Objective To investigate the correlation of microembolic signals （MES） and outcome in patients with acute ischemic stroke. Methods The patients with acute ischemic stroke were enrolled in the study. The MES of middle cerebral artery was monitored dynamically using transcranial color Doppler ultrasound. The early lesions of ischemic stroke were evaluated by MRI. The National Institutes of Health Stroke Scale （NIHSS） was used to evaluate neurological deficits. The modified Rankin scale was used to evaluate the outcome, and the stroke recurrence was recorded. Results A total of 135 patients with acute ischemic stroke were enrolled, in which, 33 were cardiogenic cerebral embolism, 49 were large artery atherosclerotic stroke, 24 were small medal occlusive stroke, and 29 were other clear causes or cryptogenic stroke. Multivariate logistic regression analysis showed that coronary heart disease （odds ratio [ OR], 5. 862, 95% confidence interval [ CI] 2. 008 - 17. 114; P = 0. 000） was the independent risk factor for positive MES within 48 hours after stroke onset, while the history of antithrombotic treatment （OR O. 376, 95% C10. 141 - 0. 998; P = 0. 045） was its independent protective factor. In addition, coronary heart disease （OR 4. 879, 95% CI 1. 257 - 18. 939; P = 0. 033）, hypertension （OR 4. 958, 95% C1 1. 029 - 23. 882; P = 0. 030） , and diabetes （OR 3. 659, 95% C11. 027 - 13. 034; P = 0. 050） were the independent risk factors for positive MES within 1 week after stroke onset. The NIHSS scores of the patients of the positive MES at baseline and 1 week and the clinical outcome at 3 months had no significant differences with the patients of negative MES, however, stroke recurrence and deaths increased significantly （P =0. 019）. Conelmiom MES within 48 hours of onset was not associated with the outcome in patients with acute ischemic stroke at 3 months, however, the incidence of endpoint events such as recurrence and death was sigaificantly higher in patients of positive MES within 3 months.