Abstract: Taking desert plant Peganum harmala as test material, under variable temperature and light cultivation, to discuss the effects of different temperature, salt stress and their interactions on seed germination and seedling growth of P.harmala,and explore the optimum temperature for seed germination and tolerance to salt stress.The results showed that temperature and salt stress and their interaction had very significant effects on the germination percent, germination rate, germination potential, lengths of shoot and root of P.harmala young seedling（P＜0.001）.The germination rate of P.harmala seeds was the highest at 30 ℃/15 ℃ and 35 ℃/20 ℃,which was significantly higher than 20 ℃/5 ℃ or 25 ℃/10 ℃（P＜0.05）.At 30 ℃/15 ℃ and 35 ℃/20 ℃,with the increase of salt, the shoot length of P.harmala seedlings increased first and then decreased,indicating that at higher temperature,low concentration of salt（50 mmol· L-1）significantly promoted the growth of P.harmalaseedlings.However,at all temperatures,the root length of P.harmalaseedlings increased first and then decreased with the increase of salt,indicating that at higher temperatures,low concentration of salt（100mmol·L-1）significantly promoted the growth of P.harmalaseedlings.Therefore,the responses of seedling root length and shoot length to salt and temperature treatments were different.