We examined whether social protests will shake people's justice belief, and its potential mechanisms. Participants were reminded of an occurrence of a social protest (vs. an ordinary event) and their justice belief toward social system as well as attitudes toward the protest was measured. Moreover, participants’ perceived group identification with the protesters was measured in Experiment 1 and manipulated in Experiment 2. The results revealed that participants with greater group identification perceived the social system as more just, and were less supportive of the protest than those with low group identification. The implications of these findings were discussed. Copyright © 2016 Taylor & Francis Group, LLC.