Litchi(Litchi Chmensis Sonn.)fruit is one of the important fruits in South China.However,the rapid postharvest browning of pericarp reduces the commodity value of the fruit and limits the expansion of the Litchi trade.Extensive researches reported that postharvest browning of litchi fruit was highly correlated with the rapid water loss of the pericarp.The water loss of fruits is usually not controlled by stomata but by cuticular waxes.The objective of this study is to understand relationship between the wax biosynthesis and pericarp browning.The wax contents,expression patterns of wax biosynthesis genes during the development and postharvest of the fruits of two cultivars,Nuomici(fast browning)and Guiwei(slow browning)were investigated.During the development,Guiwei fruit accumulated more wax and their pericarp was thicker,when compared to the Nuomici fruit.Eceriferum1(CER1),Wound inducer1(W/N1)and WAX2 expression levels were consistent with the change of total wax content.The wax structure of Guiwei was more compact and formed a net structure.During postharvest storage at 20℃ for 6 days,the weight and total wax content of Nuomic fruit decreased faster than Guiwei fruit.Storage of the Litchi fruits in 0.2-mm package reduced the pericarp water loss rate and the ketoacyI-CoA synthase(KCS),ketoacyI-CoA reductase(KCR)and trans2,3-enoyI-CoAreductase(ECR)expression levels of the fruits of two cultivars,as compared with the control fruits.Expression levels of LcECR,1ong-chain acyI-CoA synthetase(LACS),Fatty acid hydroxylase2(FAH2)and WIN1 increased with water loss rate from 0-4 days,then decreased.The up-regulation of wax biosynthesis genes appears to be a stress response of litchi pericarp water loss.Taken together,the wax layer of litchi pericarp is closely related to water loss of the fruits.The CER1,WAX2 and WIN1 expression levels were consistent with the change of total wax content.And the waxes biosynthetic of genes,LcECR,LACS,FAH2 and WIN1,appeared to be sensitive to the pericarp water loss.