Abstract: A greenhouse experiment was conducted to study effects of nitrogen fertilization on the quality of grafted cucumber(Cucumis sativus L.Xintaimici/ Cucurbita Ficifolia) and self-rooted cucumber(Cucumis sativus L.Xintaimici).We designed four levels of nitrogen: N 0,225,450 and 675 kg /hm2.The results indicated that the proper N application could increase the content of Vc,soluble protein,soluble sugar and dissociative aminophenol of both self-rooted and grafted cucumber,and consequently the quality of cucumber was improved.However,over supply N reduced the quality of cucumber.The quality of cucumber harvested at metaphase of fruiting was the best under equivalent N fertilization level.There were significant differences between the qualities of grafted cucumber and self-rooted one.The content of Vc,amylum,dissociative aminophenol,soluble protein and nitrate of grafted cucumber were higher than those of self-rooted one harvested at same period under equivalent fertilization level.Soluble sugar content in grafted cucumber in the early-days of fruiting and metaphase of fruiting was higher than that of self-rooted cucumber,while at the telophase of fruiting grafted cumber was lower than self-rooted one.