Recently, the QoS architecture in the beyond 3rd generation mobile communication system is becoming a hot topic in the area of computer networks and telecommunications. In this paper, the state-of-the-art QoS architectures are presented. By analyzing and comparing the key projects and papers published abroad, it is concluded that QoS architecture in B3G (beyond 3rd generation) system should be an all-IP, hierarchical and end-to-end framework. The main characteristics include scalability, controllable, self-adaptation and dynamic resource management. Finally, the design principals are proposed, and future works are summarized as well.