In this work, we have estimated the sea surface salinity using two techniques: (i) by combining the sea-level anomalies derived from TOPEX/Poseidon altimetry with the in situ hydrographic data (World Ocean Atlas, WOA98) and (ii) from space-borne satellite measurements of Outgoing Longwave Radiation (OLR) through the 'Effective Oceanic Layer (EOL)'. A preliminary assessment of deriving ocean surface salinity from these two techniques is presented for the Indian Ocean.