Abstract: The development of network quality of service (QoS)technologies is discussed. The QoS requirement for IPSec based security device is analyzed. Then the design of a type of architecture to implement QoS in IPSec based security device is given. Also this paper presents the two levels of classification and scheduling for data streams, which could prevent key tasks from being blocked at IPSec based security devices. This architecture combines the QoS and IPSec into a system, and provides detection, control and management together.