Abstract: The people who are in the same social circle often exhibit similar behaviors and tastes in sociology reserach. The ancillary information that difference from trust graph topology can be used for trust prediction. In this article, we propose a novel Trust Prediction Method based on Folksonomy (TPMF). Our new joint method explores the trust information in trust domain and user-sources graph and user-tagged information in folksonomy. By optimize the proposed objective function, the folksonomy information can be utilized to enhance the prediction. The extensive experiments have been conducted on real world data. The empirical results demonstrate the effectiveness of our method.