The status of total, organic and three measures of available S, i.e. Ca(H2PO4)2-S, CaCl2-S, and heat soluble S were monitored after 17 years of continuous cropping rice-wheat-cowpea with heavy fertilizer inputs in an Aquatic Hapludoll soil. Total and organic S declined to half without S but built up remarkably with S containing NPK fertilizers. The relative effectiveness to extract available S followed the order Ca(H2PO4)2 > heat soluble > CaCl2. Addition of S-bearing fertilizers enhanced S availability particularly with an increase in NPK levels.