Abstract:An improved salt tolerance black locust (Robinia pseudoacacia L. ) seedlings can be obtained after seed soakes in 250 ppm multi-effect triazole(MET),through which plant growth is inhibited, relative water content(RWC) of plants is increased , and permeability of plasmic membrane is reduced. The contents of the free prolines in the seedlings under the saline stress of the black locust through the treatment either the seeds being soaked in MET or in water may be increased . However, the content of putrescine of black locust seedlings after seed soaked in MET was reduced under stress,showing the accumulation of putrescine was related to water state of plants.