- With the development of e-commerce, choosing a proper electronic payment method has become more and more important. Competing with other payment methods on the Internet, electronic cash has much more attractive properties, such as anonymity and off-line payment, and is generally considered as an ideal electronic payment method. However, the traceability of the customer or the cash in case of double-spending or other disputes is always a difficult problem to solve. In this paper, we will focus on the problem of traceability in the electronic cash model. We propose a new electronic cash model based on group signature. In our model, traceability can be easily realized using the special property of the group signature.