The development of the second and the third generations of high by-pass ratio turbofan engines,as well as the technical measures for improving the performance of engine,are summarized and reviewed in this paper. Compared with their predecessors,the second and the third generations of high by-pass ratio turbofan engines have much lower SFC,fewer parts, lower rate of performancedeterioration and superior maintainability and reliability as well as some other advantages. To achieve this,a lot of significant advanced technologies have been developed and put in practice which are presented in brief in this paper. Finally, some remarks on aeroengine development in China have been made.