This study addresses the detection of the land degradation in the arid and semi-arid areas using remote sensing techniques. Using free data like Landsat and Shuttle Radar Topography Mission (SRTM) DEM, we mapped land degradation and its factors in Western Australia. By combining vegetation index estimated from Landsat data and geographic information calculated from SRTM DEM, the land situation was classified into five categories; healthy soil, eroded soil, heavily salinized soil, soil under early stage of salinization, and waterlogging soil/salt lake, with an accuracy of over 80%.