Grafting technique of potted walnut seedlings is common for walnut nursery tree in Bursa, Turkey. The present study was conducted to determine the effects of cultivars on graft success and development of nursery tress of potted walnuts. Foreign and native cultivars ('Adilcevaz', 'Bilecik', 'Sebin', 'Kaman I', 'Kaplan 86', Yalova 1', 'Yalova 3', 'Yalova 4', 'Chandler', 'Fernette', 'Fernor', 'Franquette', 'Hartley', 'Midland', 'Pedro') were used as scion. Walnut seedling (Juglans regia L.) was taken as rootstock. Grafting was done manually, using the methods of 'whip-and-tongue' graft at the end of February. Potted nursery trees were grown under plastic tunnel. The graft success was assessed three months after grafting. The scion shoot length (cm) and diameter (mm) were examined 100 and 150 days after grafting. The highest graft success was recorded with 'Franquette', 'Kaman I', 'Pedro' and 'Midland' (100%) and lowest with 'Yalova 4' and 'Kaplan 86' (83.33%). The scion shoot length was between 13.53-30.87 cm and the scion diameter ranged between 6.37-8.03 mm five month after grafting.