A chip-scale packaging (CSP) light-emitting device (LED) is provided with an electrode polarity identifier, and includes a light-emitting semiconductor chip and a packaging structure. A first horizontal direction and a perpendicular second horizontal direction are specified on a semiconductor-chip-upper surface. The packaging structure covers the semiconductor-chip-upper surface, a first semiconductor-chip-side surface and a second semiconductor-chip-side surface of the light-emitting semiconductor chip, and includes a first package-side surface and a second package-side surface. A first region is between the first package-side surface and the first semiconductor-chip-side surface, and a second region is between the second package-side surface and the second semiconductor-chip-side surface, wherein an area of the first region is different from an area of the second region. An orientation of the electrode polarity of the CSP LED can be visually identified by recognizing the area difference of the first region and the second region.