In an optical sheet and a backlight unit comprising same, the optical sheet comprises: a first transparent film, a first barrier layer; and an light conversion layer, wherein the first barrier layer is formed on one surface of the first transparent film, the light conversion layer is formed on top of the first barrier layer, and wherein at least one of a light-emitting composite including a wax particle and a nano light-emitting body that is disposed inside the wax particle, and a fluorescent particle is dispersed.