Abstract: Taking ‘Xizhoumi No.25’ melon as test materials, the effect of exogenous trehalose on melon seed germination, seedling growth under different NaCl and complex saline condition was studied by using different concentrations(2.5,5.0,10.0,20.0 mmol·L^-1) solution of trehalose, in order to provide reference for the melon production.The results showed that germination index and length of the seedlings gradually decreased with increasing concentration of the different salinity.The germination rate and germination potential of melon seeds were significantly decreased when the salinity was ＞75 mmol·L^-1;and trehalose soaked seeds could alleviate the damage of 75 mmol·L^-1 saline treatment on melon seeds, and the germination related indexes were improved.Pretreatment with different concentrations trehalose had no significant effect on melon seed germination under 150 mmol·L^-1 treatment of different salinity.Through the analysis and comparison of membership functions, soaking within a trehalose concentration range from 2.5 mmol·L^-1 to 5.0 mmol·L^-1 significantly increased seed germination parameters under 75 mmol·L^-1 treatment of salinity.In a word, soaking with low concentration trehalose could effectively alleviate the inhibitory effects of salinity stress on seed germination.