ABSTRACT. Macroecology of neotropical mammals with occurrence in the brazilian "Cerrado". The macroecological approach has been used recently to analyze corre lations between ecological variables in large taxonomic groups, at continental scales. A positive relationship between body weight and geographi c range size has been described as a poligonal space envelope form, that can be explained by ecological and evolutionaty constraints. However, these variables can be disturbed by spatial and phylogenetic autocorrelation effects. In this work, the relationship between body weight and geographic range size was analyzed for 80 species of Neotropical mammals present in lhe Brazilian "cerrado". Spatial and taxonomic effects were tested using a linear trend surface analysis and an ANOVA (at leveI of order), combined in a generalized model. Around 61 % of variation in geographic range size and 69% of variation in body weight in mammals ofthe "cerrado" can be explained simultaneously by spatial and taxonomic effects. The analysis 01' residuaIs of the generalized model showed that positive correlation between variables persist even atier removing these effects. Thus, variation and covariati on or traits in the maml11als or the brazilian "cerrado" agree with the general macroecological pattem proposed for another laxonomic groups such as l11aml11als, birds and snakes worldwilde. KEY WORDS . Macroecology, "Cell'ado" mammals, geographic range size, ecological and evolutionaty constraints, spatia l and phylogenetic autocorrelation A macroecologia analisa as relações entre variáveis ecológicas mensuradas em escalas grandes de tempo e espaço (BROWN & MAURER 1987 LEVrN 1992;BROWN 1995). A análise de variáveis macroecológicas, tais como o tamanho do corpo, área de distribuição e densidade populacional local das espécies, mensuradas em grandes grupos taxonômicos em escalas continentais, pode revelar processos ecológicos e evolutivos que participam na estruturação das comunidades (LABARBERA 1989;PETERS 1993; RlCKLEFS & SCHLUTER 1993;BROWN 1995).Dentre as principais relações macroecológicas, a obtida entre o tamanho do corpo (definida pela massa corpórea) e a área de distribuição das espécies tem sido descrita para diversos grupos taxonômicos, tais como insetos, peixes, aves e mamíferos, principalmente da América do Norte