Presented at the 2014 Ocean Sciences MeetingSea surface salinity (SSS) measurements by the Aquarius satellite are analyzed along with precipitation and sea surface temperatures (SSTs) to characterize and understand the SSS signature of the Madden-Julian Oscillation (MJO) over the 2-yr period for which Aquarius data are currently available. Aquarius data are able to capture the SSS signature of MJO. The spatial pattern and evolution of intraseasonal anomalies of SSS and other variables associated with the MJO life cycle are described. We show that the SSS signature of the MJO is stronger in the Indian Ocean than in the western Pacific. The relative contributions of surface freshwater flux and ocean dynamics in controlling the SSS signature in the Indian and Pacific Oceans are discussed. Salinity is found to have a substantial contribution to surface density and potential energy anomalies associated with MJO.