Abstract: A polygonal radiation module having radiating members without a light guiding board for a backlight module or a lighting device includes a polygonal optical plate with a rising area having a rising surface defined at a center thereof, a plurality of radiating members, and a diffusion plate. The radiating members surrounding a periphery of the optical plate possess radiant half-intensity angles of the radiation below 15 degrees for respectively forming optic axial directions thereof. Whereby, the optic axial directions of the radiating members face to the rising surface, and radiation fields are individually generated as pivoted by the optic axial directions to cast at the rising surface. Thus, an even radiating surface caused by a diffusion of light source from the diffusion plate could be preferably obtained even if no light guiding board is applied.