P2P online lending is an emerging economic lending model.In this marketplace,borrowers submit requests for loans,and lenders make bids on them.It has put forward new challenges to investors about how to make effective investment decisions.Bayesian network is a probabilistic graphical model that represents a set of random variables and their conditional dependencies.In the paper,we calculate the mutual information of every two variables to measure their mutual dependence and build a Bayesian network model to select loans that would pay back with high confidence.We perform abundant experiments on the data from the world’s largest P2P lending platform Prosper.com.Experimental results reveal that Bayesian network model can significantly help investors make better investment decisions than other investment models.