Age exploration(AE), which is an important part of the reliability centered maintenance (RCM), generally refers to the process of reasonably optimizing preventive maintenance task with intervals by collecting aircraft service and maintenance information while formulating the aircraft initial maintenance outline. This paper divides age exploration process into preparation stage, analysis stage and tracking stage. The general method and logical decision process of age exploration were analyzed in detail according to the type and the failure consequence of different preventive maintenance tasks, which will provide the basis for the suitability and effectiveness evaluation for aircraft maintenance outline and the continuous optimization of preventive mainte-nance task with intervals.