Two perennial temperate shrubs, Hippophae rhamnoides Linn. and Caragana intermedia Kuang et H. C. Fu, are used extensively for ecological reconstruction in the Loess Plateau, China. In this study, a water gradient experiment was conducted to assess the ability of H. rhamnoides and C. intermedia to acclimate to water stress by measuring changes in various transpirational indices. Research results showed that transpiration rate per leaf area of C. intermedia was higher than that of H. rhamnoides under the same condition. Diurnal patterns in transpiration rate for both species differed between sunny, cloudy and rainy days, between day and night-time, and decreased in relation to drought stress. The proportion of transpiration quantity in the night-time to that in the whole day was considerable. It varied clearly with species and with water supply conditions, and furthermore, it increased with the drought degree. Seasonal patterns of stomatal resistance were similar for both species under varying degrees of drought stress. In H. rhamnoides, stomatal conductance showed a strong diurnal-nocturnal pattern and displayed oscillations. Leaf temperature, photosynthetically active radiation and stomatal resistance often limited transpiration in both species. The transpiration rate of C. intermedia was more sensitive to relative humidity than H. rhamnoides.