Deyeuxia angustifolia litter along a water level gradient were studied for 450 days in Sanjiang Plain, the result showed that the decomposition mode of Deyeuxia angustifolia litter along the water gradient were all the alternate changes of fast-slow, the mass remaining rate along the water level gradient from the edge to the center of the dishing billabong were decreased and their corresponding decomposition rates increased along the water gradient, so water conditions were the important factors affecting the decomposition of the Deyeuxia angustifolia litter. The concentrations of sulfur in litters were all fluctuant changes in all study areas during 450 days and had linear relationship with dry matter mass loss. Along the water level gradient from the edge to the center of the dishing billabong, the concentrations of sulfur after 450 days decomposition were 0.588、0.508、0.404、0.359 and 0.306g.kg^-1 respectively, which were smaller than its initial concentration. The released patterns of sulfur for the Deyeuxia angustifolia litter along different water table gradient were all leaching-immobilization-release, which were regulated by the C to S ratios in the remaining matter of litter, and exogenous sulfur were immobilized when the C to S ratios were higher than 1620.34~2430.81, while sulfur of the litter were released when C to S ratios lower than 805.17~1070.4, whereas the quantities of sulfur in immobilization or release were affected by the water condition，and the quantities of sulfur in immobilization declined along

water level gradient from the B to F, while the quantities of sulfur release increased.