Soil moisture is water held on the spaces between soil particles. It is one of the important variables in controlling the exchanges of water and heat energy between land surface and atmosphere. Soil moisture observation data is not enough and the direct measurement time is short in Korea, which is a limitation to present whole area of regional scale. In this study, soil moisture will be retrieved by SMOS (Soil Moisture and Ocean Salinity) satellite. SMOS is ESA (Europeans Space Agency)’s Earth explorer mission launched in November 2009. Main instrument is MIRAS (Microwave Imaging with Aperture Synthesis) with 69 antenna receivers distributed on Y-shaped deployable atenna array and hub. It measures horizontal and vertical polarizations sequentially. However, There are a lot of missing data about soil moisture, because of RFI (Radio Frequency Interferences) in Korea. In order to recovery, we need to establish soil moisture algorithm using SMOS brightness temperature suitable regional features of Korea.