Korea Expressway Corporation established standard of LED lighting fixture in Dec. 2013. To raise compatibility, the standard requires a fixed form and it is applied to street lights and tunnel lights, etc. Because streetlight has different circumstance condition from tunnel light that is down light and exposed to constant wind velocity over height of 8 meters, in case of LED module which has the same shape, characteristic of radiant heat can be different. In this paper, we designed 25 [W] LED Module that is designated by standard of Korea Expressway Corporation and analyzed characteristics of radiant heat about natural convection and forced convection. It is dropped 10.12[$^{circ}C$] that max temperature is decreased by increasing 20 mm of bended height of heatsink at the condition of natural convection. Radiant heat characteristic of bended height 35 mm became 78.08[$^{circ}C$] at the condition of natural convection, 55.30[$^{circ}C$] at the condition of forced convection so that 22.78[$^{circ}C$] is decreased that is 29.1[%] decrease. Bended height 55mm became 67.96[$^{circ}C$] at the condition of natural convection, 48.04[$^{circ}C$] at the condition of forced convection so that 19.92[$^{circ}C$] is decreased that is 29.3% decrease.