The physiological and biochemical characteristics of Humulus scandens seedlings under NaCl stress (0, 100, 200, 300 and 400 mmol/L NaCl) was studied. The study results indicated that: (1) the growth of H. scandens seedlings has severely inhibited with the increase of NaCl concentration, and the root, stem and leaf dry weight, single leaf area, specific leaf area(SLA) and root/shoot ratio(R/S) also reduced. (2) The P_n, G_s, C_i, T_r and Ψ_w in leaves of _{H. scandens} seedlings were all decreased, but the values of L_s and WUE_i obviously increased , and the effects strengthened with the increasing of salinity concentration. (3) The NaCl stress obviously had a lower Chl a and Chl b contents CAT activity, and a higher superoxide dismutase (SOD), peroxidase (POD) activities and malondialdehyde (MDA) content. It shows that the antioxidant enzyme system of H. scandens seedlings has a positive response strategy to NaCl stress. (4) The minimum fluorescence (F_o), variable fluorescence (F_v), maximum fluorescence (F_m), electron transport rate (E_TR) and photochemical quenching coefficient (qP) of H. scandens seedlings were also significantly increased in different NaCl concentrations, but the effective photochemical quantum yield (F_m′/F_o′) and nonphotochemical quenching coefficient of PSⅡ(qN) effectively decreased. In summary, there was no apparent effect of H. scandens seedlings under low NaCl stress（100 mmol/L）. However, gas exchange parameters, chlorophyll contents, chlorophyll fluorescence parameters, antioxidant enzyme activities were inhibited with the increase of NaCl concentration. Especially, high concentration of NaCl stress seriously affected the growth of H. scandens seedlings, their physiological and biochemical indexes showed a gradually decreasing trend.