The salt tolerant germplasm Crossostephium chinense and the two wild species of Chrysanthemum, Chrysanthemum indicum (Tiantangzhai) and (Shennongjia), along with two cultivars of Chrysanthemum (‘Fanhuasijin’ and ‘Hanluhong’) were treated with 1/2 Hoagland nutrient solution containing 200 mmol·L^-1 NaCl and their physiological response that changed with the increase of saltstress time were compared. The related physiological indexes of each material were measured at 0, 5, 10 and 15 days after salt stress and the physiological responses of each material were compared, in order to preliminarily explore the physiological salttolerance mechanism of C.chinense. The results showed that the contents of chlorophyll (Chl), net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r) and the peroxidase activity (POD) in five species decreased with the increase of saltstress time, while C. chinense had the minimum decrease or a significantly different changing trend from other 4 Chrysanthemum species. In the meantime, the content of malondialdehyde (MDA), proline and the activity of superoxide dismutase (SOD) increased with the time, and among them the MDA of C. chinense increased least. The changing trend of intercellular CO₂ concentration (C_i) varied in different germplasms. The study has shown that the chlorophyll content and the membrane system were relatively stable under salt stress, and the net photosynthetic rate maintained at a certain level, which may be the main reasons that the salt tolerance of C. chinense was stronger than that of other Chrysanthemum species.