Brassica chinensis L.is a typical green leafy vegetable which is easy to senesce and yellow after harvest.The effects of different concentrations of melatonin (MT) (0.2,0.4,0.6,0.8 mmol/L) on the storage quality of Brassica chinensis L.were studied.The results showed that MT treatment could effectively delay the senescence,keep the good color,delay the increase of weight loss rate and yellowing rate,and keep the higher contents of chlorophyll,vitamin C,soluble solids and reduce sugar.In addition,MT treatment also significantly increased the activities of peroxidase and polyphenol oxidase.Among the four different melatonin concentrations,0.6 mmol/L melatonin was the most suitable for the storage and preservation of Brassica chinensis L.The results provided theoretical basis and technical support for the storage and preservation of Brassica chinensis L.