This research is an initial step in a long term study of vegetation communities of the Brasilia National Park. The vegetation contained within this reserve is representative of an increasingly threatened savannah ecosystem (known locally as cerrado), which extends across much of central and northern Brazil. An intensive study focusing on both the principal woody vegetation communities of the National Park and their associated soils, was undertaken. Data was collected from two years of continual fieldwork between October 1990 and 1992. This in itself is the first systematic survey of its kind ever to be carried out within the National Park of Brasilia. Vegetation and soils were selected for analysis from a total of twenty six sample sites using the point quarter centre method (PCQ). There was considerable heterogeneity in the species sampled. While this can be largely attributed to soil moisture gradients, other factors like variations in fertility and topography, or the presence of ironstone layers and sandstone outcrops, are all seen to be influential. Even so, the dynamics of these vegetation communities cannot be fully appreciated without considering the important role of fire in this context. This study confirms that the cerrado ecosystem has a highly diverse flora. Nine different plant communities were identified within the National Park; cerrado open scrub (campo sujo), cerrado scrub (campo cerrado), cerrado scrub with emergents (Vochysietum), campo rupestre, cerrado rupestre, cerrado sensu strictu, as well as dry, wet and flooded gallery forests. Even within these different communities, (and this is especially true of the gallery forests), both the distribution of species and their diversity was seen to be high. In all, a total of 380 species, with individuals having a basal girth exceeding five centimetres, were recorded.