In this paper

the SPOT-4/5 satellite images

taken as the information sources

were studied on the plateform of the softwave ERDAS 8.7 with a variety of image processing methods to address the geological investigation of a railroad in western mountain area in Yunnan.According to the regularity of the geological disasters distribution in the mountain area

the characteristics of the remote sensing images

and the knowledge of earth science

this paper proceeded the remote sensing image interpretation of some sections of the railroad and has found the effects on the railroad due to landslides

mud-rock flows

and avalanches.The research result in this paper may provide a scientific basis for addressing the railroad.