Abstract:Fullsib family is an important material for genetic analysis. Sixtytwo fullsib families of the first generation of Pacific white leg shrimp, Litopenaeus vannamei, are constructed by natural mating and seventeen of them are studied in growth traits. Results indicate no significant correlation of hatchability and survival rate of postlarvae to the weight of female parent. Seven families are significantly faster in growth than others in the 40 weeks of growth traits, and the order of their weight is A02>A11>A01>A17>A06>A08>A16. These seven faster families are 23.2% higher than the mean value of all 17 families in growth rate (g/week) during the 40 weeks traits (P<0.05). By comparison of each family, families A01, A02 and A11 are 25.5%, 31.6% and 31.0% larger than the mean value of the seventeen families respectively. Moreover, these three families display the smaller coefficient of variation (CV), and the CV values in the middle of growth period are 11.58%, 9.95% and 8.48% respectively. The CV values of the three families are <5% in the later growth period. Therefore the results indicate that they are three families with excellent economic properties. These results are helpful for further selective breeding of fastgrowth line of Litopenaeus vannamei.