As a primary space environmental factor,weightlessness influences the astronauts psychologically and physiologically.The purpose of this paper was to review the research progress of the effects of weightlessness/simulated weightlessness on animal behavior,the changes in neural plasticity,neural cells’ structure,function,proteins and genes in microgravity environment.The trends of neural system researches in the field of space medicine was prospected which may provide reference for the current researches in space medicine.