This paper, summarzes the remote sensing investigation work of mudflow gullies along the Chengkun railway line. It includes: the work steps of using remote sensing images to identify mudflow gullies, macroscopic qualitative judgment and statistical analytic judgment. As compared with conventional methods, the use of remote sensing images not only increases greatly the accouracy of judgment, but also saves a great deal of finanical and material resources as well as manpower.