Research on the responses of plants functional characters to the changes of groundwater level caused by topographical differentiation was important for revealing the maintenance mechanism of plants to adapt the decline of groundwater level and developing ecological restoration of vegetation in northwest China. Five sandy shrubs that grow and dominate in the Hailiutu River Basin typical grassland, namely Salix psammophila, Salix cheilophila, Caragana korshinskii, Artemisia ordosica, and Hedysarum leave, were investigated. The characteristics of biomass allocation, root distribution and physiological response to changes in groundwater level of five species under different topographic conditions were explored (namely, flat land, interdune and dune, and uplifting topography). The results showed that: (1) S. psammophila belonged to a deep root type, and its survival depended on both the water in the shallow soil layers and groundwater; S. cheilophila, C. korshinskii, A. ordosica and H. laeve belonged to shallow root types and thus depended on water in shallow soil layers. (2) In the flat land of lake beaches, predawn shoot water potential (ψ_pd), midday shoot water potential (ψ_m), stomatal conductance (g_s), maximum quantum yield (F_v/F_m) and apparent quantum efficiency of photosynthesis (Φ), net photosynthetic rate at light saturation point (P_s) and photosynthetic photon flux density at light compensation point (I_c) of S. psammophila and S. cheilophila showed no significant difference. The ψ_m, g_s and F_v/F_m of A. ordosica and H. laeve displayed significant differences. (3) On the small dune and interdune lowland with different groundwater levels, ψ_pd, ψ_m, P_s and I_c of S. psammophila showed significant differences; ψ_pd and g_s of S. cheilophila showed significant differences; and ψ_m of C. korshinskii and A. ordosica showed significant difference. Other physiological traits of these shrubs showed no significant difference. (4) The correlation analysis between physiological characters of S. psammophila and groundwater level indicated that the g_s and P_s decreased significantly, Φ increased significantly, and I_c did not change significantly with groundwater level declining. In conclusion, the responses of five shrub species with different root distribution to changes of groundwater level are significantly different. The results can provide reference for groundwater resource management to native vegetation restoration in arid ecosystems that depend on groundwater.