Network coordinates provide a practical and efficient way to estimate latencies among hosts in the network. In this paper, we study the problem of designing and implementing a Network Coordinate System (NCS). To combine advantages from both Vivaldi and GNP algorithms, we propose our Network Coordinate System. We implement such a system on PlanetLab test-bed all over the world. Network distances can be predicted based on our Network Coordinate System. By performing experiments on PlanetLab, we show that NCS can predict network distances quickly and accurately. We believe that our system is a viable step to provide a network service of distance prediction in the Internet.