To evaluate the effects of oxalic acid treatment on the chilling injury and metabolism of membrane lipids of post-harvest Hami melon. Melons were dipped in different concentrations of oxalic acid （OA） with 0， 15 mmol/L at 25 ℃ for 10 min and stored at 3-5 ℃ for 42 days. Chilling injury index and cellular membrane permeability of fruit， activities of LOX and PLD， contents of MDA and fatty acid constituents of membrane lipids in pericarp of melon fruits during storage were determined. Results showed as compared to the control fruit， there were lower fruit chilling injury index， activity and the expression of pericarp LOX and PLD MDA and oleic acid （C18：1）contents in Hami melon fruits pre-treated with OA treatment. The relative contents of unsaturated fatty acids in pericarp， such as linoleic acid （C18：2）， linolenic acid （C18：3）， arachidonic acid （C20：4） and membrane-bound Ca2+ content increased， while the contents of saturated fatty acids in pericarp， such as palmitic acid （C16：0） and stearicacid （C18：0） decreased （except for 35 d）， and index of unsaturated fatty acids （IITFA） and unsaturated degree of fatty acids in pericarp increased. The result suggested OA treatment alleviated the chilling injury and enhanced the chilling tolerance of Hami melon fruits may be due to the increase of membrane-bound Ca2+ content， the decrease of LOX and PLD activities and coding enzyme gene expression during storage， which may reduce the degradation of unsaturated fatty acids of membrane lipids and maintain higher unsaturated degree of fatty acids.