In order to grasp the level and trend of various technical parameters of turbofan engine correctly. The models and corresponding programs for performance calculations and evaluations of size and weight of turbofan engine were set up. The technical parameters were collected of fifteen foreign typical turbofan engines from 2 to 4 generations, which were evaluated with the programs mentioned above so that the level and developing trends of these parameters were obtained. Then, the technical parameters were predicted of the advanced turbofan engine of next generation. Based on the developing trends of the technical parameters, the possible engine integration design directions of next generation advanced turbofan engine are explored, which helped to indicate its developing trends and method of integrated design.