The past traditional Word-of-Mouth (WOM) researches show when people feel uncertain or have negative comment to products they purchase, they always compare their decisions with the other people or give their negative comment about the products as an outlet of feeling. Otherwise, after the aforementioned comparison, if one found that the other people got a better deal, generally the person would defense himself by providing untrue message to the other people. With the development of information technology, WOM has become a critical link between virtual communities. People gain and provide information much faster than before. At present there are not many researches on eWOM, especially not on actual content. The main objective of this paper is to discuss the relationship between the two variables of Cognitive Dissonance and Social Comparison. The study shows what people’s reaction is after having experienced an unhappy feeling and be affected by internet comparison information. Both qualitative and quantitative data analyses are performed. The outcomes show that the upward/downward comparison interfere the independent variables and creates a significant interaction effect. Those who experience cognitive dissonance have more intention to provide dishonest comment when they compare with people who get a better deal. But if the comparison target’s deal is worse, they feel relax and less disappointed. The interviewees’ opinions and comments are studied and stated in the paper. The research is constructed on social comparison on Internet. It can be provided as a reference for the other relevant survey, be used on virtual community administrative or as a tool to understand how cognitive dissonance and social comparison affect one’s purchase thru Internet.