This paper examines the central role of social and political institutions behind motivations and strategies of ethnic Chinese Singaporean investment in Hainan, China. Drawing upon 22 case studies of Singaporean firms in Hainan, we show that Singaporean investment in Hainan is embedded in Chinese business networks and their associated institutions. At the personal level, direct investments are largely motivated by the cultural attachments of Singaporean Hainanese to Hainan. Their small- and medium-sized joint ventures largely reflect the characteristics of ethnically-based Chinese business networks that stress connections, or guanxi. Similarly, the influence of social organizations (e.g., clan associations) and government institutions (e.g., public and quasi-public agencies) on Singaporean investment strategies in Hainan reveals the significance of ongoing social relations institutionalized at the broader societal level.