To explore the influence of applying exogenous mannitol and sorbitol on muskmelon seedling growth.and ion balance under salt stress，the study chose muskmelon ‘guimi 12’ as test materials and sand culture with Hoagland nutrient solution(CK0).100 mmol/L NaCl was used to simulate salt stress(CK1)，and different concentration of mannitol and sorbitol were added.The processing of melon seedling growth and the change of ion balance were observed.The results showed that under 100 mmol/L NaCl stress(CK1)，compared with CK0，the underground fresh weight，dry weight，total root length，root surface area，root volume，K+ / Na+，Ca2+/ Na+ and Mg2+/ Na+ of muskmelon seedlings decreased significantly.Addition of 0.4 mmol /L mannitol significantly increased the concentration of Ca2+ and Mg2+ in the stem and leaves of muskmelon seedlings，but did not increase the concentration of Na+ and did not decrease the concentration of K+. The ratio of Mg2+/ Na+ was significantly increased，while the ratio of Ca2+/ Na+ and K+ / Na+ were about the same as CK1. Addition of 0.4 mmol /L sorbitol significantly increased the overground fresh weight，the root length，root surface area，root volume，of muskmelon seedling，but significantly decreased the concentration of Na+，increased the Ca2+ and Mg2+ concentration，and the ratios of Mg2+/Na+，K+/Na+ and Ca2+/Na+ in muskmelon seedlings under salt stress were increased. These results indicated that appropriate concentrations of sorbitol and mannitol could alleviate the damage of salt stress to muskmelon seedlings.Under experimental conditions，0.4 mmol/L sorbitol was the best treatment to alleviate the effects of salt stress on root and ion balance of melon seedlings.