Abstract: Vetiver grass (Vetiveria zizanioides) has an extensive root system and is consequently used worldwide for water and soil conservation. However, soil compaction resulting in high soil bulk density negatively influences root growth. In order to understand the adaptation of vetiver grass to soil compaction, the effects of soil of different bulk density, 1.20 g/cm³ (D_1.20), 1.35 g/cm³ (D_1.35) and 1.58 g/cm³ (D_1.58), on the root morphology and biomass of vetiver seedlings were investigated using soil columns. The results showed that shoot and root dry weight, root:shoot ratio, root surface area, root length density and root volume density decreased with increasing bulk density, but that average root diameter increased. High bulk density influenced the spatial distribution of roots; more roots grew in the upper (0-6 cm) and lower (18-24 cm) soil horizons under the D_1.20 and D_1.35 treatments, suggesting that vetiver typically produces a deep root system but that root growth is inhibited by high soil bulk density, confining roots to the upper soil horizon (0-6 cm). The average root diameter in the D_1.20 and D_1.35 treatments decreased but increased in D_1.58 with increasing soil depth. It is concluded that vetiver grass could tolerate moderately compacted soil.