Abstract： The ability of alfalfa seeds to convert various concentration of 1-aminocyclopropane-1-carboxylic a cid (ACC) and ethephon (ETH) to ethylene was found much lower under saline (c（NaCl）=0.25 mol/L) than under no-saline condition. Addition of exogeno us ethylene (φ=3 μL/L) could trigger rapid germination of alfalfa seed stressed by 0.25 mol / L NaCl solution for 48 h, but did not affect Na+ conte nt in NaCl-stressed seeds. During the imbibition of seeds, addition of exogenou s ethylene also did not affect the water uptake of the NaCl-stressed seeds. The results showed no obvious difference in water or Na+ content in the seeds str essed by NaCl in either the presence or the absence of exogenous ethylene. Exoge nous ethylene greatly increased respiratory rate and ATP level in NaCl-stressed alfalfa seeds. It is presumed that enhancement of ATP formation is an importan t mechanism by which the inhibition of germination of salt-stressed alfalfa see ds is alleviated by ethylene. Mechanism of alleviation of inhibition by ethylene in salt-stressed alfalfa seeds was discussed. Fig 6, Tab 1, Ref 21