The uniqueness of the co-operational behavior in human society may be related to the function of social norms. Norm Activation Theory believes that social norms have a great influence on human pro-social behavior only when activated, which exactly expresses the process of the Third-party Punishment. To explore the psychological mechanism of the norm activation process, an experiment was designed which contained both a Dictator Game (DG) and a Third-party Game (TP). TP was used as a way to activate the social norm of fairness. The norm activated subjects took both TP and DG during the experiment while the non-activated ones took only DG. A significant enhancement of the pro-social behavior in DG was found in norm activated subjects after TP. We also found that social responsibility played an important role in norm activation. Subjects with higher social responsibility presented more pro-social after activated. The result revealed that a third-party subject punished the behavior against social norms even the punishment was costly. This phenomenon was explained as an arouser of both the responsibility to protect social norms and anger about the destruct of social norms. Further more, higher Social Responsibility a person had implied a stronger activation of social norms, which brought more anger and pro-social behaviors. With experimental errors and explanations of other theories eliminated, this result revealed that there were two important processes in norm activation: the arouser of the responsibility to protect social norms and the inspirer of the anger about the destruct of social norms. These two processes implied that social norm activation was not only a cognitive awakening process but also an emotional inspirer. Therefore, responsibility, which contained both cognitive and emotional component, might be paid more attention to in studies about the activation of social norms.