Karelinia caspica(Pall.)Less. Var. Asteraceae andAtriplex tatarica L. Var. Chenopodiaceae are dicotyledonous halophytes. They both have a broad distribution in Xinjiang region of China. This paper is about the drought resistance characteristics and differences of K. caspica and A.tatarica combining pressure-volume technique (PV technique), aims to further understanding the growth and distribution characteristics of halophytes. The results showed that the predawn water potential and relative water content were higher in Atriplex tatarica than that of K.caspica, so A.tatarica had higher water saturation deficit (RWDBB0BB) than K.caspica; Both of them were strong Midday depression of transpiration type, while A. tatarica was low water potential dehydration tolerance type, K.caspica was high water potential dehydration detention type; A.tatarica had higher turgor (ψ), elastic modulus (ε max)and osmotic adjustment ability than K.caspica, so it can maintain the stability of water potential and prevent cell dehydration. To some extent, A. tatarica had stronger drought resistance than K.caspica.