An optical lens having a fluorescent layer is provided. The optical lens is adapted for being employed in an LED packaging structure. The optical lens includes a substrate, at least one lens body, a lens shade, and a packaging member. The substrate is positioned at a bottommost side of the packaging structure, and the lens shade is positioned at a topmost side of the packaging structure. The lens body is positioned over the substrate and beneath the lens shade. A plurality of light emitting units are disposed on the substrate. The packaging member is adapted for packaging the substrate and the lens shade. The lens body is secured by the packing member so as to be positioned over the light emitting units. The lens body includes a fluorescent layer buried inside the lens body, and the lens body is positioned apart from the light emitting units for a certain distance.