We have developed the three-dimensional optical simulation software for optical devices: LED lamps, photocouplers, photointerrupters and so on. Other simulation software can not calculate the optical efficiency and the directional characteristics of a LED lamp, but this simulation software can calculate them by modeling the LED chip. And we have established a simulation model of scattering plane on the basis of measured values. In this paper, we describe an overview of this three-dimensional optical simulation software and an example of results using this simulation software.