Abstract: In the present study, the absorption dynamic parameter of NO-3 in Suaeda physophora Pall., which were pretreated in different concentration of NaCl and NO-3, were investigated. The main results were as followed: The uptake of NO-3 of Suaeda physophora Pall. was in accordance with Michelis-Menten equation. And the absorption dynamic parameter of NO-3 showed that: salt stress changed the uptake kinetics parameters of NO-3 to different extent, the addition of salt increased Vmax and enhanced Km as compared with the control, which resulted from the number of the carrier and membrane environment. As to the low-affinity system, pretreated with high NO-3, the absorption rate of NO-3 of Suaeda physophora Pall. was significantly restrained; pretreated with low NO-3, NaCl stress accelerated the the absorption rate of NO-3 for Suaeda physophora Pall.