This paper focuses on investigating the spectral changes of EEG in overtrained athletes through self-normal controls and thus establishing a digital quantitative approach to recognize the EEGs of overtrained ones. In addition, the VEPs of those with overtraining were analysed.During a period of 11 months, EEGs of each of 20 athletes were recorded separately at their overtrained and normal states. A control group was formed of 19 normal athletes, each of whom two EEG exams were made too. The EEG was taken at rest, during periodic flash stimulation and after hyperventilation (HV). Paired t test was performed on the power spectra of EEGs and VEPs, and Fisher classifier were established by the differences of spectral features (DSF) between the two EEGs in each of almost all of the 30 cases.The relative powers of the EEGs in the overtrained cases showed a significant increase (P