The methord of using pretreatment fitration and adsorption-prirrary ultafiltration-ion exchange-secondary ultrafiltration techogical.process to prepare water for injection fromtap water,river water,well water, fish pond water was studied. Through the examnination of pharmacopeia prescribed items,the examination of bactriology,spectrum analysis,the quality of water product prep-ared by using this technological process accorded with the stipulations of water for injection of Chinese pharmarcopeia edition No.21.It has been proved to be an efficient technological process for preparing water for injection.