Test of Xinfeng sub-population of the main growth breeding population of Pinus taeda was assessed for traits. Selection was carried out using tree volume. The results showed that genetic gains of combining selection were higher than that of family selection. Giving the selection rate as 4/100, then the genetic gains for combined selection and family selection were 48.6% and 21.8% respectively. For 25/100 of selection rate, the genetic gains were 30.3% and 11.1% respectively. Possibility of at the age of six years, aimed at improvement for productive deployment and establishment of selection breeding population, was discussed. It raised selection for the establishment of the next generation breeding population that could be realized only when most trees in the test stand of sub-population reach the age of fruiting.