Collecting, correlating and extracting network performance information is an important premise for effective grid applications and services. Based on the intrinsic relationship between the Internet and grid computing, we extend the network performance monitoring activities in Internet to grid scenario and develop a scalable, interoperable grid network measurements and monitoring system (GMMPro) which is mainly derived from the principle of Simple Network Management Protocol (SNMP). The advantages of SNMP-based monitoring are manifolds: (1) The interface between this monitoring architecture and its client (other grid services or applications) is simple and has been wildly accepted in Internet environment. (2) Multiple Measurements and Monitoring Engines (MMEs) are introduced to provide system scalability and flexibility. (3) The configurable feature of GMMPro could provide special configurable service for particular application needs and the preferred passive measurement methodologies enhance system?s scalability in large-scale deployment. Some preliminary measurement results in practice are also presented in the paper.