Abstract: In order to study the effects of alcohol drinking on electroencephalography (EEG) during driving, a system of indicators for EEG analysis were set up based on the real-time EEG data of drivers collected by a neuroscan EEG system under virtual scenes made of sharp curves, emergency stop belts, obstacle zones and straight line segments. After fast Fourier transform, the mean powers of delta wave (δ), theta wave (θ), alpha wave (α), middle fast wave, beta wave (β), and gama wave (γ) were calculated, and the proportion of the power in each frequency range to the whole frequency range was obtained. Then, the differences of the combined indicator (α+θ)/β were compared between drunk driving and non-drunk driving, and all the indicators were analyzed by the paired sample t-test. The results show that alcohol drinking affects significantly the theta wave, alpha wave, and gama wave, with t-test values being less than 0.01; but does not affect significantly the rest of EEGs, with t-test values being more than 0.05. Among the three parameters affected significantly, only the difference of gama wave before and after drinking reduces gradually with the blood alcohol concentration (BAC) decreasing. When the BAC dropped to 40.5 mg/100 ml, the difference of gama wave was 1.12%.