This investigation was carried out for two seasons (2007 and 2008) on 11 years old trees of Washington navel orange trees grown in El-Bramon research farm at Dakahlia governorate and budded on four citrus rootstocks namely, Sour orange (SO), Volkamer lemon (VL), Troyer citrange (TC) and Rangpur lime (RL) to evaluate their growth, fruit set, yield, fruit quality and fruit storage on the trees. The following results were:          1- Trees of Washington navel orange trees grafted on Volkamer lemon rootstock appeared that the larger growth significantly (as tree height, canopy circumference, trunk circumference, spring shoots number and leaf area), followed by Rangpur lime, Troyer citrange, Sour orange rootstock, respectively.          2- Volkamer lemon stock gave significantly the highest values of final fruit set, yield, fruit weight, fruit size, total acidity, total soluble solids / total acidity ratio and ascorbic acid content, while Rangpur lime stock followed by Troyer citrange significantly increased for these traits comparing with Sour orange rootstock. In two seasons, initial fruit set, L/D ratio, T.S.S and fruit rind weight in the second season were not significantly affected with previous rootstocks in this study.              3- As for storage, the highest of loss percentage in fruit weight were found in fruits collected from budded trees on Sour orange stock and the lowest values were observed with Volkamer lemon rootstock  in both seasons. Total acidity percentage significantly decreased when storage. Trees of Washington navel orange grafted on Volkamer lemon rootstock gave the highest of total acidity, but the lowest values were in collected fruits from budded trees on Sour orange rootstock. Meanwhile, no significant differences were detected on rind weight loss percentage and TSS % in the two study seasons between tested showed rootstocks.           Generally, the four rootstocks could be descending arranged according to their study character is tics of Washington navel orange fruits as follow: Volkamer lemon, Rangpur lime, Troyer citrange and Sour orange, respectively.           Also, Volkamer lemon rootstock could be recommended as a suitable rootstock for Washington navel orange trees under Delta region conditions for its superiority on Sour orange rootstock.