It is a basic problem of computer science to get the accurate time. Compared with other technologies， network timing is simpler， more economical and more efficient. The design and implementation of a highly efficient network timing software mainly based on the network time protocol（NTP） is given by proceeding from computer time resolution， clock skew， frequency drift， as well as software development skills. Tests in a substation local area network（LAN）and on real Internet through ADSL show that the accuracy achieved is quite spectacular， especially so in LAN.