As known by heart, LED's can be stated as the most important light sources that are faced in today's lighting technology. Because of their flexible structures, in addition, LED's can be used both indoor/outdoor lighting applications and inside of the different luminaire types. As similar to the conventional light sources, very detailed optical analyses must be carried out for the LED luminaires, too. But for the high power LED's, the heat is a prior problem and besides the optical design, thermal design is very crucial at the process of luminaire design utilizing high power LED's. In this paper, in order to realize optimum thermal analyses for LED based luminaires design, it is aimed to determine the required design processes and to investigate current computer based thermal analyses methods. Furthermore, it is objected to explain thermal analysis methods for LED based luminaires. Beside these, insufficiencies in LED related standards are tried to be explained and the requirements for the new ones are stated.