Online consumer reviews are important for consumers when they make purchasing decisions. However, the large volume of online reviews makes it difficult for consumers to identify those helpful reviews. The influencing factors on online review helpfulness have drawn great attention from different research fields. In recent years, online review websites start to exhibit more features of social media. For example, some websites allow users to integrate with other social media accounts. The influences of such social factors, however, are rarely studied in the literature. Drawing on a dataset from Qunar.com, this paper explores how social network integration and reviewer network centrality influence online review helpfulness through a negative binomial regression model. Our results show that both factors have a positive effect on review helpfulness, and that network centrality positively moderates the effect of social network integration. Our research results provide important implications for reviewers, industry practitioners, and online review websites.