Abstract: In this paper, the principle and method of the synthetic aperture radar differential interferometry (D-InSAR) are described firstly, the surface deformation information caused by underground coal mining has been observed in the Xishan Mine Area. The deformation maps are displayed by the ARCGIS software, and the deformation value of corner reflectors can be extracted, which is consistent with the value from GPS. It verifies the feasibility of the high-resolution TerraSAR-X images in monitoring the surface subsidence caused by underground coal mining.