Peer to Peer (P2P) lending is a new business model. People lend money to borrowers through internet where they judge the borrowers by information provided by the website. This paper looked at four angles of the business, and aims to find how age, gender, and location influences the interest rate, participator number, success rate and probability of funding success. Meanwhile, we also do the survival analysis of the likelihood of funding success. Thirdly, this paper examined the substitution or complementary effect of A-shares trading and P2P lending; market return of A-shares is negatively significantly related to biding times of P2P lending. This can be the evidence of the substitution influence of these two investment choices. As stock market is acting as the barometer of the economy, online P2P lending can be a substitute to the investment of A-shares when the market is not good.