the paran？ river basin (states of goiás and tocantins, brazil), with 5,940,382 ha, has many different plant physiognomies, including the deciduous forest on limestone outcrops which has not yet been studied in this region. in this paper we present the structure of the tree community of a deciduous forest on a limestone outcrop (13o 49'34'' s; 46o 41'55'' w) in s？o domingos municipality, goiás state, brazil. twenty-five plots of 20m × 20m (400m2) were randomly placed on lines 100 m apart. trees with dbh > 5cm were tagged, measured, and identified to species. in the phytosociological study, 588 individuals were sampled. a total of 36 tree species, belonging to 31 genera and 21 families were registered. the species with the highest importance value (iv) were: tabebuia impetiginosa (43,81), aspidosperma pyrifolium (35,64), luetzelburgia sp. (21,77), commiphora leptophloeos (18,79), myracrodruon urundeuva (15,79), pseudobombax tomentosum (13,42), combretum duarteanum (13,04), luehea divaricata (12,24), cabralea canjerana (11,99), ficus pertusa (11,82), jacaranda brasiliana (11,68) and aspidosperma sp. (10,57). together these make up 73.5% of total iv while the 24 remaining species constitute 26.5%.