With broccoli as test material,a field experiment was carried out to investigate the effects of 0.15 mmol/L salicylic acid(SA) on physiological characteristics,yield and quality of broccoli under different lower limits of flood irrigation.The results showed that:(1)The leaf relative water content and water potential and chlorophyll content decreased,while the blade penetration proline(Pro) and malondialdehyde(MDA) and soluble protein(Pr) content were gradually increased with the lower of irrigation limit;the flower ball weight and vitamin C content(Vc) decreased with the lower of irrigation limit;on the contrary,the nitrate and soluble solids contents were increased.(2)When spraying 0.15 mmol/L SA significantly increased the leaf relative water content and water potential,osmotic adjustment substance content,yield and quality,while reduce the membrane lipid peroxidation product and MDA content,of which 45% irrigation limit is the most obvious,60% followed,75% minimum.Thus,the suitable concentration of exogenous SA enhance its resistance to drought stress by improving water in broccoli leaves and leaf osmotic adjustment content and reducing membrane permeability,and the lower limit of 60% with spraying 0.15 mmol/L SA handled better.