A light-emitting device comprises a textured substrate comprising a plurality of textured structures, wherein the textured structures and the textured substrate are both composed of sapphire; and a light-emitting stack overlaying the textured substrate, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein one of the plurality of textured structures comprises a top portion and a bottom portion, wherein a first distance between a first projection of the top portion on the bottom portion and the bottom portion at one side is different from a second distance between a second projection of the top portion on the bottom portion and the bottom portion at another side.