Given the prevalence of internet and web 2.0, SNS(Social Network Service) market is growing rapidly. IT providers which focused marketing point on network hub have become to disseminate SNS mainly now. Many users are using the various functions of SNS to communicate each other or share the information. At this point, identifying the influencing factors to WOM(Word-Of-Mouth) of SNS is very important. In this paper, we aim to examine the effects of perceived variables on the WOM of SNS. In order to analyze the antecedents, we selected perceived factors such as perceived usefulness, perceived easiness, perceived enjoyment and perceived crowd. For statistical analysis, we surveyed real users of SNS. As a result, all antecedents of WOM showed significant influence and among the variables the perceived enjoyment has top standardized coefficient. In addition, perceived crowd has significant on perceived easiness, perceived enjoyment but not on perceived usefulness. The result of this research can be useful guidelines to increase SNS Market.