Abstract: This paper discusses the basis, kernel, key points and guarantee of RCM, and shows that to go further into job in these four aspects is important. Moreever, it is pointed out that in order to bring the positive factors in every aspect of design, manufacture, operation and maintenance into play such as to raise the aircraft maintanence level successively, the structure of the maintenance system should be reformed by the use of principles and approaches of system engineering and having the whole aircraft engineering system in mind.