A method of fabricating slant reflector with bump structure, at least comprising the steps of: providing a substrate; forming a photosensitivity material layer on the substrate; patterning the photosensitivity material layer to form m groups of pattern (m≧1, m is positive integral), and each group of pattern includes a plurality of bumps with different bottom area; and jointing the bumps to form a slant surface with bump structure. The photosensitivity material layer is either orderly or randomly patterned to form m groups of patterns. The step of patterning the photosensitivity material layer includes exposing and developing. The invention utilizes one photo-mask with particular pattern to fabricate the bump structure in a simple way.