Abstract Abstract The pursuit of higher fuel-efficiency and lower carbon emission has promoted economic efficiency to the chief consideration for civil aviation industry.Meanwhile,due to the development of material science,further reduction of aircraft's weight without losing strength has become applicable,and thus,making such pursuit practical for aircraft manufacturer. Based on the knowledge of civil aircraft designing and the study of the course,this report has proposed a concept for the next generation's "mid/short-range twin-aisle aircraft", which applied elliptical fuselage and a V-shaped tail.Marketing research shows huge potential requirement of productions with 250 seats in the near future.According to this design requirement,we determined the overall configuration and designed landing gear and aircraft systems.Two optional turbofan engines were selected for the propulsion systems. Based on aerodynamic and flight dynamic analysis,the flight characteristics are calculated. Analysis of aviation economics are conducted in the last part. Keywords:Mid/short-range,Twin-aisle,Conceptual DesignAbstract II Abstract The pursuit of higher fuel-efficiency and lower carbon emission has promoted economic efficiency to the chief consideration for civil aviation industry. Meanwhile, due to the development of material science, further reduction of aircraft’s weight without losing strength has become applicable, and thus, making such pursuit practical for aircraft manufacturer. Based on the knowledge of civil aircraft designing and the study of the course, this report has proposed a concept for the next generation’s “mid/short-range twin-aisle aircraft”, which applied elliptical fuselage and a V-shaped tail. Marketing research shows huge potential requirement of productions with 250 seats in the near future. According to this design requirement, we determined the overall configuration and designed landing gear and aircraft systems. Two optional turbofan engines were selected for the propulsion systems. Based on aerodynamic and flight dynamic analysis, the flight characteristics are calculated. Analysis of aviation economics are conducted in the last part. Keywords: Mid/short-range, Twin-aisle, Conceptual Design