Investigating the impact of plant species on sulphur (S) availability in the rhizosphere soil is agronomically important to optimize S fertilization. Bulk, rhizosphere soils and the roots of Weld-grown rape and barley were sampled 7 times (every fortnight), from March to June, at plant maturity. Root carbon (C) and nitrogen (N) in water extract, along with soil SO 4 2¡ -S, labile soil organic-C (HWC) and -N (HWN) in hot water extract, as well as soil arylsulphatase activity were then monitored. The average concentrations of both HWC and HWN were observed in the following decreasing order: rape rhizosphere soil >barley rhizosphere soil >bulk soil. In parallel, the average contents of water extractable-C and -N in rape roots were higher than those in barley roots. These results suggest that soil C and N contents in hot water extract (including rhizodeposition) were correlated with C and N released by roots. Great ARS activities found in rape rhizosphere soil were accompanied by great SO 4 2¡ -S mineralization over time. Finally, bulk and rhizosphere soils of rape and barley were pooled from the seven samplings and incubated with the corresponding pooled root water-soluble C of both plant species and glucose-C. After 1 and 9 weeks, a greater net S mineralization (gross mineralization -immobilization) was observed with rape root water-soluble C than with barley root water-soluble C and glucose-C. Conjointly, we found a higher average value of ARS activity in rape rhizosphere than in barley rhizosphere soil. Our Wndings suggest that plant species, via their rhizodeposition, determine the dynamic of S in soil.