Privacy and anonymity on the Internet are gaining increasing attention from both the scientific and the large Internet user community. WonGoo is a peer-to-peer scalable anonymous communication system that provides strong anonymity and high efficiency with layered encryption and random forwarding. It reduces the message overhead and lengthens the covert path. In this paper, we firstly describe the system briefly and evaluate its payload. Then we present a detailed security analysis of the system. The results reveal that the degree of anonymity provided by the system increases with the increase of forward probability and the path length, and reduces with the increase of corrupted nodes. In addition, it is hard to increase its anonymity signi ficantly only by increasing the size of the system.