Data capturing has been the foundation of many network critical application, such as intrusion detection system and network management application. This paper introduces how to implement data capturing in different network situations, including wired LAN and wireless LAN; introduces the data capturing engines in both Unix and Windows system and compares the differences between them, presents the critical techniques of data capturing used in high-speed network, introduces how to discover data capturing behavior in network and finally point out the trend of the future development.