Marisol is a new highly productive Clementine cultirar that has been Introduced to the Egyptian Hart suture industry. This study was carried out during two successive seasons (2005&2006) at Hort Res. Institute, Fruit Handing Department, Giza Governorate, to detemiine the behavior of Marisol cultivar fruits during development and maturation. Manisol (C dernentina Hod. ex Tan.) trees grown in a private farm at Ismailia Governorate, grafted on Sew orange, Canto Waage, Cleopatra mandarin and °Mimeo rootstods were selected for this study. Fruit samples were taken during fruit development at the first week of October and repeated at weekly intervals until commercial harvest. Fruit physical and chemical diaracterisres during development and maturation were determined. Fare weight, TSS contents and TSS/acid ratio significantly increased, Mile fruit firmness and total acidity decreased gradually and significantly dunng growth development. On the other hand, fruit volume, fruit gravity and juice content were nearly constant during the first maturation gages, and then began to decrease with the extension of fruit age, at over npening stage. Fruit color changed cfirectly from yellowish green to greenish•yellow to yelow with advanced fruit age. However, fruit coloration was poor at the earlier stages of maturation process and required to be degreened. Ascorbic acid ccatent of fruit increased gradually and significantly untg it readied the maximum nearly at the optimum maturity stage, then began to decrease with the increasing of fruit age. Fruits produced from trees on Carew, Cleopatra and Crewel° rootstocks were heavier, more volume, less gravity, more developed color less linnniss, less juice content, higher total soluble solid content, less total aridity content and higher total soluble sold/total acidity ratio than that produced from trees on Sow orange, while rootstock types had no effect on fruit contents of ascorbic add. Marisol fruit produced from trees on Canto and Caramel() followed by that on Cleopatra rootstocks reached maturation one week earlier than that produced from trees on Sour orange when TSS / Acid ratio reached more than 9:1, (nearly after 168 • 175 days from full bloom, during the last week of October or the first week of November). While that on Sour orange readied maturation at one week late-. Moreover, data also indicated that fruit quality deteriorated quiddy with delaying harvesting process after reaching maturity stage.