This study was carried out on Hernandina fruits were taken from a private farm at Wady El-Mulak region, Ismailia GOVCMOrate during two successive seasons (2005:2006 &2006:2007) to determine the behaviour cf Hemandina cultivar fruits on four citrus rootstocks during growth development and maturation under the Egyptian conditions. Hernandina trees grafted on Sour orange, Carrico Orange, Cleopatra mandarin and 'Swingle' °Menet reotstods were selected for this study. Fruit samples were taken during growth development at the first weak of December (210 days from full bloom) and repeated at weakly intervals until commercial harvest (259 and 238 days from full bloom during the first and the second season respectively). Fruit physical and chemical characteristics during growth development and maturation were determined. Hernandina clementine frult wbght, TSS contents and T5$/total acidity ratio of fruit significantly Increased while fruit firmness, total acidity of fruit juice decreased gradualy and sigmficanUy during growth development On the other hand, fruit voime, fruit gravity and juice content were nearly constant during the first maturation stages, and then began to decrease with the extension of fruit age, at over ripening gage. Fruit color changed directly from greenish-yeknv to yellow then to orange net the increasing of fruit age. Ascorbic acid content of fruit increased gradually and significantly with the advanced time until readied the mzoimum nearly at the optimum maturity stage, then began to decrease with the increasing of fruit age. Fruits produced on Canto, Oeopatra and Otrumelo reetSrofikr were IleaW weight and more volume and development of color, less gravity, flmvxss, Juice content and total acidity content but higher total soluble solid contents and total soluble solids / total acidity ratio than that produced on Sour orange, while rootstock types had no effect on five content of ascorbic add. Hernandina fruits on Carrizo and Otrumelo followed by those on Ocopatra =Mode reached maturation one week eerier than that on Sour orange, when 755 / Add ratio readied to more than 12-13:1, (nearly after 230-238 days from fun bloom, during the first week of lanuary).while that on Sour orange readied after 238:245 days after full bloom. Hanover, data also indicated that fruit quality deteriorated quickly with delayed harvesting process after reaching maturity Stir.