Research work was conducted on the size-class structure and the spatial distribution pattern of the natural regeneration seedlings, which belong to the virg in forest, successive cutting forest and clear cutting forest of Larix gmelinii in north Daxing' anling in Inner Mongolia.The results show that the size-class st ructure of the natural regeneration seedlings bo th in the virgin forest and in the successive cutting forest belong to the stable structures of the population, which favors the continuous regeneration of the population, w hereas the size-class seructure of the natural regeneration seedlings in the clear cutting forest belongs to the declined st ructure of the population, which goes against the continuous regeneration of the population.The spatial distribution pattern of the natural regeneration seedlings in the three typs of forests assumes an aggreg ate distribution.And by the degree of agg regate distribution the highest of the three forest types is the virgin forest, the clear cutting forest comes second, the successtive cutting forest third.This paper also puts forw ard some sug gestions about management of Larex gmelinii.