A brief overview of research progress about manned spaceflight to Mars program in several countries was given. Investigation of some domestic and international programs and scenario of manned spaceflight to Mars was put up. Some fundamental and basic ideas about determination of future manned spaceflight to Mars were put forward. One of programs and scenario of general design, including trajectory and spaceship of manned spaceflight to Mars was discussed and put out. Especially, more important parameters of the total mission energy required and the total mission duration of the trajectory in several mission windows were calculated. The detail results of trajectory design, including transfer Mars injection, Mars orbit insertion, Mars surface descent, Mars surface ascent, transfer Earth injection, Earth orbit insertion and reentry Earth, and Mars spaceship design, including propulsion module, transfer habitation module, Mars landing module and Earth reentry capsule were obtained.