Abstract: To investigate the characters of the electroencephalogram(EEG) for fatigued drivers,the situation of fatigue driving was simulated using a car simulator,the EEG for the driver was recorded by an EEG recording instrument,and the EEG data and waves obtained.Methods of average power spectrum and correlation dimension were applied to analyze these data.Characters R and D in the EEG for the fatigued driver were found.The degree of fatigue of the driver can be estimated by the characters shown by the EEG.