Despite of abundant studies, little is known about controllable variables of flaming. In order to address this challenge, this study explores flaming mechanism in terms of three perception factors (perceived risk, anonymity and expected emotional reaction) and finds a controllable variable which moderates that mechanism. The findings of this study are referred that public self-awareness, perceived identifiability and affective social presence have significant effects on flaming in terms of perception factors, while information overload moderates the influence of public self-awareness on flaming. From those results, it is important to preventing information overload in order to control flaming. More implications and limitations are discussed on last section.