To provide a better understanding of mobile phones as a recruitment tool in collective actions, this study explores the use of mobile phones for mobilizing protest in China. Using in-depth interviews and investigating four cases in which Chinese people employed mobile devices to recruit participants for protests, this study observes that mobile communication in China embodies guanxi, the indigenous social tie in Chinese society that introduces reciprocity as an influential facilitator of collective actions. The embedment of reciprocity facilitates the proliferation of mobilizing calls, legitimizes mobilizing appeals, generates obligations and consolidates solidarity for collective actions. The study concludes with a consideration of the relevance of mobile phones for the embedment of reciprocity in social ties in the mobilization of collective action in authoritarian regimes such as China.