A light-emitting device includes a light-emitting unit comprising a top surface and a first side surface; a light-transmitting layer covers the top surface and the first side surface; a wavelength conversion structure disposed on the light-transmitting layer; a protective layer covering the second side surface and the light-transmitting layer; and a reflective layer surrounding the protective layer. The wavelength conversion structure includes a wavelength conversion layer, a first barrier layer disposed on the wavelength conversion layer, a second barrier layer disposed under the wavelength conversion layer, the wavelength conversion layer, the first barrier layer, and the second barrier layer are collectively formed a second side surface.