Daphniopsis tibetana Sars (Crustacea: Cladocera: Daphniidae) is a low-medium saline lake cladoceran showing wide but patchy distribution in plateau saline lake in Asia. In China, D. tibetana widely distributes in saline waters in Tibet, Qinghai, Xinjiang. In the present paper, D. tibetana were collected from Lake Namuka Co. The animals can be live in diluted seawater via acclimatization. Effects of temperature, salinity and body length on ammonia excretion rate of D. tibetana were studied under experimental condition in laboratory. The results showed that ammonia excretion rates (NR) were 0.061-0.092mg/(g h),0.022-0.092 mg/(g h) and 0.017-0.083mg/(g h), respectively, in salinity, temperature and body length experiment. The results also indicated that NR was positively related to the salinity and temperature. However, NR was negatively related to the body length. The relationship of NR with the salinity, temperature and body length can be expressed by the model of NR=0.0359Ln(T)-0.0185, NR=0.0535e0.0213Sand NR=00568L-1.4154, respectively.