CONET V2.0 is a network system under microkernel environment. Compared with the traditional monolithic kernel, microkernel provides a different approach to construct operating system, which leads to different implementation of those modules running under such environment. In this paper, the architecture and design of CONET V2.0 are outlined, and then the design and the implementation of SOCKET, which is one of the application interfaces for the network system, are presented in detail.