Abstract: 【Objective】 To investigate the effect of exogenous salicylic acid （SA） on the leaf anatomical structure of Hami-melon under single salt stress （NaCl）. 【Methods】 In this experiment，the new Hami-melon variety Nasimi was used as the test material，and the optimum concentrations of NaCl and SA were screened by seed germination test. The changes of leaf thickness，upper and lower epidermal thickness，palisade and sponge thickness were analyzed，and the ratio of palisade thickness to sponge thickness，scattered rate （SR） and cell tightness rate（CTR） were calculated and correlation analysis was performed. 【Results】 Under NaCl stress，the leaf thickness and upper and lower epidermal thickness of Hami-melon showed a trend of increasing，the palisade thickness were loosely arranged，and the leaf flesh gap was getting larger. After foliar spraying of SA，leaf upper and lower epidermal thickness，leaf thickness， palisade thickness，ratio of palisade thickness to sponge thickness increased，and spongy thickness and SR decreased. The palisade thickness and CTR were highly significantly positively correlated，and spongy thickness and SR were highly significantly positively correlated under the two treatments （P< 0.01）. 【Conclusion】 100 mmol/L NaCl was used as the stress concentration and 0.25 mmol/L SA was used as the mitigation concentration. SA treatment could alleviate the stress by regulating the indexes related to leaf epidermis and leaf flesh anatomical structure