Presented at the 2017 International Geoscience and Remote Sensing SymposiumA new debiased non-Bayesian methodology has demonstrated to be very effective for the retrieval of Sea Surface Salinity (SSS) from brightness temperature (TB) measured by Soil Moisture and Ocean Salinity (SMOS) interferometric radiometer. Applying this methodology it is possible to retrieve SSS values in marginal seas or cold waters where the operational retrieval does not. Another important improvement is the possibility of defining a SMOS-based climatology to characterize spatial biases. Recently, using data from the Soil Moisture Active Passive (SMAP) mission, JPL has started to produce a new 9-km resolution TB product. The existence of such product offers the possibility of increasing the spatial resolution and quality of the mentioned SMOS SSS product using fusion techniques. The aim of this work is to produce high resolution SSS maps in marginal seas derived from the fusion of SMAP 9-km TB and SMOS non-Bayesian debiased SSS products.