THIS EXPREMENTS was carried out during two successive  ……..seasons 2015 and 2016 at the nursery of pomology department, Faculty of Agriculture, Cairo university, Egypt. The study was aimed to investigate the effect of two fators namely i.e, pre-grafting incubation and grafting materials position during callusing on grafting success of flame seedless grapes onto Salt Creek rootstock. Callusing was carried out in three positions i.e, horizontal, upright and upright down either with or without pre-grafting incubation. The results showed that either pre-grafting incubation or callusing at uprightposition increased significantly callus percent and degree, sucker number, rooting rate, bud break percent during callusing period and grafting success percent. The interaction, betweentreatments revealed thatcallusing at uprightpositionaccompanied with pre-grafting incubation gave the best results in this respect. It can be concluded that callusing at uprightposition either with or without pre-grafting incubation increased grafting success significantly compared to callusing at horizontal or upright down position.Chemically, higher grafting success is accompanied with lower phenols, reducing sugars and total indoles. It may be concluded that there is no antagonistic effect between root and callusformation in grafted cuttings. Also, upright position for incubation the grafted cuttings are better than pre-grafted incubation in increasing grape grafted cuttings.