Fire is the most common disturbance in natural forested ecosystems and plays a significant role in ecological succession of forest communities.Fires often burn in the Da Hinggan Mountains(also known as the Greater Khingan Mountains) where frequent high-intensity fires rapidly transform the landscape.These fires have extensive and long term effects on the spatial distribution of natural Larix gmelinii forest.This study looks mainly at gaps formed by fires of different severity in natural L.gmelinii forest and is based on data from records collected at the Pangu Farm,Tahe Forest Bureau,Da Hinggan Mountains in July 2011.We describe the dynamic processes which create tree spatial distribution patterns of natural L.gmelinii forest in Pangu farm.Our research looked at how fires of varying severity influenced the spatial distribution patterns of natural L.gmelinii forests by analyzing gaps in plots.We selected suitable class parameters at a landscape scale and combined with the state of tree spatial distribution patterns.We defined three phases,the gaps phase,immature phase and mature phase.The results show stands which suffered moderate fire disturbance are moved into the gaps phase of the forest cycle;these stands retain only a small amount of medium and large diameter live trees of L.gmelinii.Pioneer species reveal aggregative distribution in the newly created patchwork of gaps of different sizes;the distance between the patches was the shortest of the three phases and the shapes of the patches themselves are very complicated since moderately intense fire leaves a significant and irregular accumulation of gaps within any particular plot.The research plot,in a stand that was burned with low intensity fire,retained most of its L.gmelinii,and continued to develop along the normal lines of forest succession.Low intensity fire allowed L.gmelinii to continue to maintain its aggregative distribution.A large number of pioneer species invaded into the area burned with low intensity fire.The low intensity burn area had the smallest gap patches of the three phases studied.The shape of these small gap patches was the most uniform and the separation between the gap patches was the largest of the three phases.The unburned plot with no known history of fire disturbance was a mature phase forest and included a complex patchwork or network of gaps of different sizes.The unburned L.gmelinii community had changed from an aggregative distribution into a uniform distribution.Because fires burn with different levels of intensity,the undergrowth was transformed into gap patches.The spatial distribution pattern had changed with fire distribution.As the level of fire disturbance declined in a particular stand the area moved from the gaps phase,to the immature phase and then the mature phase in the forest cycle.