In order to clarify the regular pattern which Periploca sepium Bunge responds for the salt stress and investigate the optimum saline concentration and light condition for the growth of P.sepium Bunge,we measured the light response of photosynthetic parameters,such as net photosynthetic rate(P_n),transpiration rate(T_r),stomatal conductance(G_s),water use efficiency (WUE) and light use efficiency(LUE),to P.sepium Bunge in different saline concentrations with CID portable photosynthesis system.The results show:(1)The LCP of P.sepium Bunge varies from 21.89～65.05 μmol·m^-2·s^-1 under different of saline concentrations.It means that P.sepium Bunge is between the negative and positive plants.With the different of soil salinity,the photosynthesis of P.sepium Bunge for illumination intensity shows some adaptability and plasticity.The photo assimilation ability of P.sepium Bunge is stronger under the 50 mmol·L^-1 of saline concentration.The accumulation of dry matter is enhanced and the plants show salt resistance to a certain extent.(2)The light salt stress less than 50 mmol·L^-1 can improve the P_n,G_s,WUE and LUE of P.sepium Bunge leaves,and the salt stress has inhibitory effect to T_r,and the inhibitory effect is positive related with the saline concentration.(3)In order to maintain the normal growth,the fitting saline concentration of soil is less than 50 mmol·L^-1,and the optimum PAR is between 1 000～2 000 μmol·m^-2·s^-1,and the illumination intensity to maintain the high WUE and LUE is separately 800 μmol·m^-2·s^-1 and 100 μmol·m^-2·s^-1.