Abstract: Objective To study the difference between the nonlinear eigenvalue of epileptic patients and normal subjects for accurate identification of epileptic EEG signal.Methods Multivariable phase space reconstruction technique was employed to analyze the EEG of epileptic patients for estimating the correlation dimension(D₂), which was one of the most often used parameters in quantitative discretion of complicated nonlinear dynamics system.Result and Conclusion The correlation dimension is an important eigenvalue for epileptic EEG identification.