The purpose of this paper is to explain the indoor thermal radiation environment of the human body in detail. Using a 3-D human body model, shape factor calculations between a human body and surroundings are executed. First, the shape factor between the human body and each surface of the room is calculated. The human body is placed in the center of the room. The shape factor results are visualized by VRML. Generated VRML images indicate the influence of thermal radiation, which the human body receives from the room surfaces. Second, the shape factor between the human body and surroundings (the room surfaces and some people) is calculated. Some "people influence" on the subject's human body is shown. And the shape factor variation with body position in the room is shown in detail.