Abstract: The development of aero-engine technology makes it necessary to study the versatile core engine technology.Versatile core engine technology not only increases the number of the common parts of the developed engines,reduces its research and development periods,but also improves the performances of all the types of the developed engines.Aero-engines of different kinds with a certain power/thrust class could be derived from the corresponding versatile core engine with a certain mass flow amount.The design of versatile core engine must make a compromise between strength and aero-dynamic performance,and its components must be able to work effectively and stably within a wide range of operation;moreover,the versatile core engine should allow some small changes in the follow-up development.This paper discusses the issues for the turbine stage numbers and the compressor form in the conceptual design of a medium-small scale versatile core engine.