Social lending, also known as Internet acquaintance lending, is a product segmentation of P2P lending. It refers to the lending transactions started among relatives and friends via the Internet. In contrast to the rapid rise of social lending in the industrial circle, there is little empirical research on social lending in academia. Based on social exchange theory, this paper studies the influencing factors of investment intention towards social lending. The results show that trust, perceived credit risk, perceived emotional risk and profit anticipation significantly affect the intention to invest. While the borrower factors such as social interaction, psychological cost, reciprocity specification; platform factors such as perceived anonymity, perceived collection measures, indirectly affect the investment intention through the intermediary variables. This paper makes up the deficiency of relevant empirical research and provides a direction for the future development of social lending.