The Soil Moisture Experiment in the Luan River (SMELR) in 2018 was carried out toward developing of new satellite mission opportunities in China. It was designed to explore several scientific and technical questions regarding to soil moisture remote sensing and its application. Various passive, active microwave and optical observations were collected by both airborne and satellite platforms. Ground-sampling of soil moisture/temperature, vegetation and roughness were conducted close in time to the airborne acquisitions at 200 to 2000 m scales. Ground-based measurements of microwave emission and scattering, emissivity and reflectance spectra, evapotranspiration and radiation were conducted along the flight areas. Moreover, two in-situ networks that cover the Shandian (100×100 km) and Xiaoluan (25×25 km) river basins were established to provide continuous measurements of soil moisture and temperature profiles (3-50 cm). This paper describes the overview of the experimental design, obtained data sets and initial results.