Social protests have played an important role in the process of political change in Taiwan. Although many studies on Taiwan's social movements are qualitative analyses focusing on specific cases, few explain the variation in the frequency of social protests within Taiwan. To fill this empirical gap, this paper draws hypotheses from the theory of political opportunity structure and subjects it to empirical tests using a unique dataset of subnational protest events. First, the empirical analyses show that the frequency of local protests tends to be higher in a locality where the Democratic Progressive Party (DPP) is in power. Secondly, the results demostrate that, in an election year, local citizens have stronger incentives to protest. Finally, we find that the share of the seats of the DPP in a locality council does not have a significant effect on local protests. Overall, this study facilitates a better understanding of the development of Taiwan's civil society and provides important insights regarding the political processs in new democracies.