Abstract: Germination tests were conducted in two nurseries for two successive vearsby using slash pine seeds of 3 different size classes. The results show that seed sorting has changed the seed size and weight distribution of seed lots,which influenced the speed of seed germination,and then the early growth of the seedlings. In the germination stage and early growing period,there were significant differences between the seedlings from different seed size classes,but there was no difference in the late growing period.Using different size ofseed lot could not achieve the objective of increasing the seedling quality and uniformity.Innursery practices,the genetic makeup of seed lot would be of the first factor considered,then the seed size or weight.