Abstract: Based upon field experiments and by sub-film trickle technique，the soil environment of cotton rhizosphere including moisture，heat，and air conditions is studied．The results show that film mulch can increase soil temperature and the cotton root system nearly grows horizontally in upper soi1．Furthermore．it is found that sub-film trickle irrigation is advantageous of air transfer in the soil beneath film since the irrigational technique results in the alternative rows of dry soilzones and wetted soil zones in field．With the sub-film trickle irrigation technique to cotton in field，the irrigation water for the cotton has been saved by 40％ ～ 50％ ．and the cotton yield has been increa sed by 20％ ．