In this study, we adotped survey methodology to collect online auction buyers and sellers’ different feedback reaction in different feedback mechanisms to determine certain non-rational feedback reactions such as “retaliatory feedback”. McNemar test is used to testify if different feedback mechanism induces different degrees of non-rational feedback reaction. According to the analysis, it is found that different feedback mechanisms indeed lead to different degrees of non-rational feedback reaction. Results showed that feedback mechanism of online auction is not only establishing trust in the Internet, but also inducing a mix of other factors. As a result of different feedback mechanisms having different connotations, this study provides implications to academic research in feedback mechanism and trust, as well as practical implications to online auction site operators for implementing their feedback policies.