Although spectrometric oil analysis(SOA) is a widely applied technique for wear condition monitoring of lubricating system

this single monitoring technique is difficult to accurately predict some damages or failures in oil wetted system including bearing fatigues of aero-engine.In this paper

two techniques including SOA and auto debris classifier were applied to synthetically monitor a certain aero-engine

the Dempster-Shafer(D-S) evidence theory was used to implement fusion diagnosis

and an engine oil monitoring expert system was developed to carry out fusion diagnosis.Finally

some examples were analyzed;the results indicate that synthesized monitoring and fusion diagnosis is an important approach to increase the reliability for forecasting failures of aero-engine.