The vegetation of the Nylsvley Nature Reserve in the Transvaal Mixed Bushveld is classified hierarchically by the Braun-Blanquet Method of vegetation survey. The vegetation is seasonal grassland and deciduous savanna with four floristically distinct major groups of plant communities: (I) grasslands and broad-leaved savannas on non calcareous sandy soils on elevated sandstone and felsite areas; (2) microphyllous thorn savannas on calcareous, clayey, bottomland alluvial soils and termitaria thickets; (3) grassland and thorn savanna on calcareous self-mulching vertic soils; and (4) secondary communities on long abandoned native settlements and recently ploughed land. Seven primary communities with 12 community variations and 4 subvariations, and three secondary communities are described on the basis of 216 releves. The survey was carried out at two levels of detail, an ecosystem study area in the broad-leaved savanna being surveyed in more detail, floristically and structurally, than the rest of the Reserve.