The Great Xing′an Mountains fire in 1987 affected more than 1.33×106 hm², creating a mosaic of burn severities across the landscape, which strongly affected the post-fire vegetation succession. In addition, undulate landform and anthropogenic disturbance inevitably influenced post-fire vegetation succession. In this paper, a typical area was selected for a case study, including two forest farms, covering more than 1.2×105 hm². In order to reveal how the forest changed in 2000 (13 years after fire), compared to 1987 (pre-fire), and to find out the relationship between the forest succession and affecting factors, forest crown density was selected as the criterion, and forest type, fire severity, silviculture practice, elevation and topography gradients were designed as affecting variables. With the support of GIS software, each variable was classified and entered the multivariate regression model. The result showed that the forest crown density changed notably in 2000 compared with that of pre-fire, and all the variables significantly affected the forest crown density. The most important affecting variable was elevation, which was positively correlated with forest crown density. The next was fire severity which was negatively related with forest succession. The effects of topographic factors and silviculture practices on forest crown density were relatively small.