Abstract: To purify and rejuvenate the variety of C.reticulata Blanco "Fuju",pomelo was used as the pollen parent and Fuju the maternal plant to cultivate nucellus seedlings.Applying the top-grafting-exchanging-variety technique,the flowering and fruiting age of the nucellus seedlings was advanced by 2-3 years.The juvenile period of Fuju was cut short and the fruit quality improved while maintaining its original desirable characteristics.After years of observation and assessment on the top-grafting plants of nucellus seedlings,considerable quality variations were found among nucellus embryo plants.Three strains of superior varieties were identified: "Xinnong 1","Xinnong 2" and "Xinnong 3".They had high fruit yield,large fruit size,bright peel color,less seeds and high content of soluble solids.For example,Xinnong 1 strain contained 14.2% soluble solids,averaged 8 seeds,and weighed 118 g per fruit.This variety is recommended for expanded cultivation.