Abstract: Compared with slash pine (Pinus elliottii) introduced early and native masson pine (Pinus massoniana), the research was carried out for 21 loblolly pine (Pinus taeda) family introduced from America and 4 loblolly pine family introduced earlier. The results showed loblolly pine grew the most quickly and most characters between family had significant differences. The heritability was quite high and the genetic variation coefficients were most above 4.5%. The growth quantity of 5 years varied significantly among sites. The effect on family and the mutual effect on gene and environment were also significant, but the mutual variance was small. From the two dimensional scatter plot of regression coefficient and productive index, No 25,19 and 18 family not only grew quickly but also revealed mean stability. They could adapt themselves well to all kinds of habitats and be popularized widely. No 20, 17, 23, 24, 22 and 16 family only grew quickly in fine circumstances.