Abstract: Baseline is the foundation for aero engine condition monitoring and fault diagnosis. It is hidden in the monitoring systems provided by OEM and is a barrier for monitoring and performance analysis of the engine by operators.Amount in-depth and extensive researches are conducted on the accurate baseline definition, the acquisition of baseline data and the establishment of baseline equations. Several baseline data mining methods are compared and var ified with actual flight data, providing theoretical a useful reference for engine monitoring and analysis.

Key words: aero-engine baseline, neural network, SVR, Gauss-Newton interative method, least square method