Abstract: In this paper, the author put his emphasis to the importance of brain science research in space flight based, on the flight experinces and laboratory investigationsdur-ing the past twenty years. The theories and techniques developed in author's laboratory for astronaut brain function research are briefly summerized. The viewpoints on brain evolution in the gravitational field, the principle of frontalization of brain function and the problem of extraterrestrial intelligence are also stressed. Finally, a space brain science research program is suggested.