This paper mainly studied on using activated sludge process with zeolite to upgrade the traditional secondary treatment plants. In this process, zeolite acted as ammonian sorbent and microbial carrier firstly, and then composed zeolite and biological complex to improve denitrification of anaerobic zone and nitrification of oxic zone. In the anaerobic zone, the influent contained a lot higher ammonian concentration. The zeolite adsorbed ammonian, it increased carbon nitrogen ratio and facilitated denitrification. While in the oxic zone, adsorbate concentration of mixed liquid decreased owing to biodegra dation by the action of salinity and microorganism. Thus, it striked a balance between adsorption and desorption of zeolite with ammonium, and zeolite with ammonium released constantly ammonian to renew.