Social media has become an increasingly popular arena for political candidates to run political campaigns. The current study aims to examine how political candidates formed online social networks with each other on Facebook. The context of the study is the 2016 legislative election (candidate sample size n=196) in Taiwan, which is the only Chinese society that has a democratic voting system. First, social network analysis is used to explore size, density, reciprocity, and transitivity of their online networks. Then, ERGM is used to analyze the factors underlying the formation of social ties in their online networks, including personal, election, and structural characteristics. Finally, hierarchical multiple regressions are performed to examine the effects of candidates’ structural positions (closure, cross-partisanship, and brokerage) in the peer network on the election outcome while controlling for candidates’ personal characteristics, key election features, and the amount of news coverage in traditional media. Overall, our results suggest that there is a statistically significant positive relationship between the closeness of peer social networks and election results. However, we did not find significant impacts of the cross-partisanship and the brokerage related to the election results. Implications were also discussed.