Spiral of silence has been published for 30 years, and been tested in many areas, however these test are not all qualified. This study aims to interpret spiral of silence theory and to inspect if there are any misuse in these test. First, we interpret these theory form the origin of the theory and it¡¦s deducing process, and built an theory model. Then inspect those test based on this model. The result discovered that most of these test stressed on testing people¡¦s willingness to speak out, and misleaded to compare one¡¦s opinion and one¡¦s perception of majority. This comprehension gap may comes from the wrong variable definition in the operational models. For this sake, this study offered a theory model to overcome this gap.