Abstract: A novel purinylpyridinylamino-2,4-difluorophenyl sulfonamide derivative, a pharmaceutically acceptable salt thereof, a preparation method thereof, and a pharmaceutical composition with an inhibitory activity against Raf kinase, containing the same as an active ingredient are provided. The purinylpyridinylamino-2,4-difluorophenyl sulfonamide derivative of the present invention effectively regulates the activity of B-Raf kinase, and thus may be useful for preventing or treating cancers induced by the over-activation of Raf kinase, especially various melanoma, colorectal cancer, prostate cancer, thyroid cancer, ovarian cancer and the like.