Abstract: At present，the European Space Agency’s Soil Moisture and Ocean Salinity（SMOS）satellite is severely perturbed by radio frequency interferences，and much more present over China. In this paper，a radio frequency interference detection algorithm based on SMOS satellite data is proposed. SMOS L1-c level data is analyzed by the proposed algorithm and get L-band radio frequency interferences′ location distribution over China，the sources of partly radio frequency interferences，the characteristic of their periodicity over time and brightness temperature over orientation，and so on. The results can not only be as a reference for the application，the radio frequency interferences detection and suppression of L-band on-orbit remote sensing sensors of China，but also provide reference information for Radio Regulations.