The aim of this study was to obtain a basic information about the graft union formation in relation with growth characteristics between 'Rootpac' rootstocks and almond, plum and apricot varieties. In this trial, 'Rootpac-R', 'Rootpac-90', 'Rootpac-70', 'Rootpac-40', 'Rootpac-20' rootstocks and 'Nonpareil', 'Ferragnes' almond, 'Aprikoz', 'Hacıhaliloğlu' apricot and 'Black Diamond', 'Papaz' plum cultivars were used as plant materials. 1, 4 and 12 months after T budding, graft samples were evaluated microscopically and macroscopically. Transverse sections (20-45 µ) were cut by rotary microtome. At transverse sections that taken from 4 and 12 months after grafting were observed forming of callus in all combinations from scion and rootstocks, being broken of necrotic layer as different densities and occurring of cambial differentiations and cambial continuity between scion and rootstock were established. However, tissue development differences were observed in the combinations of 'Aprikoz' and 'Hacıhaliloğlu' apricots grafted on 'Rootpac-R', 'Black Diamond' plum grafted on 'Rootpac-40', and 'Black Diamond' plum, 'Papaz' plum, 'Aprikoz' and 'Hacıhaliloğlu' apricots grafted on 'Rootpac-20'.