Abstract: The research objects are primitive broad-leaved Korean Pine, over-cutting forest and artificial-natural larch mixed forest in Jingouling Forest Farm, Wangqing Forest Bureau, Jilin Province.The investigation dataare complied for the variance/average value ratio law and other kinds of aggregation index.We found that the number of regeneration seedlings in primitive forest is the most, the over-cutting forest is the second, the artificial-natural mixed is the least.The size-class structure of the natural regeneration seedlings both in the primitive forest and in the over-cutting forest belongs to the stable structures of the population, the artificial and natural larch mixed stand belongs to the declined structure of the population.All of the spatial patternsof seedlings in the three forest types are aggregate distributions.And by the degree of aggregate distribution the highest of the three forest types is the over-cutting forest, the artificial-natural mixed forest comes second, the primitive forest third.This study provides the basis for the natural management of artificial forest.

Key words: primitive forest, over-cutting forest, artificial & natural mixed forest, regeneration, distribution pattern