Abstract: This study aims to research the adaptation characteristics of Picea crassifolia and Picea mongolica in arid desert region, and choose proper forest plants for the arid desert region. The authors took twoPicea species as the materials, measured their water physiological characteristic under normal soil water condition, moderate soil water stress, and severe soil water stress. The results showed that under different water stresses, the free water content, leaf water potential, tissue water content, relative water content of the two species decreased, water saturation deficit, ratio of bound water content to free water content and bound water content increased, and leaf water-holding ability reduced. With the change of season, water parameters of the two species changed regularly affected by the external environment. The variation of the tissue water content was not significant from July to September, the bound water content, ratio of bound water content to free water content showed an increasing and then decreasing trend from July to September; the relative water content showed an increasing trend; the free water content decreased and then showed an increasing trend. In the early days of water stress, the difference of water water-holding ability of the two species was not significant. With the prolonging of water stress time, the difference of water-holding ability increased and the water-holding ability of Picea crassifolia was less than that of Picea mongolica. Picea mongolica had stronger water physiological characteristics by analyzing the water parameters.