CLNSS07Agent-based on-line negotiation technology has the potential to radically change the way e-business is conducted. In this paper, we present a formal model for autonomous agents to negotiate on the Internet. In our model, the negotiation process is driven by the internal beliefs of participating agents. We empirically identify the relative strength of a group of belief updating methods and show how an agent can change its behavior by adjusting some critical parameters. The advantage of our model is that it is flexible and easy to implement. To show different "personalities", one only need to plug in suitable "subjective beliefs" to one's agents. Our results provide directive reference on how these beliefs should be chosen and what values of the related parameters should be assigned.