This paper introduces an implementation of a clock synchronization method for NTP(Network Time Protocol). NTP is widely used and an effective application protocol in maintaining time synchronization over the network. But the performance of NTP depends on Operating System(OS) and on the real time property of OS because of working on the time management functions provided by the general-purpose OS. But, currently available OSes' real time properties are restricted. So the needs of the embedded time synchronization systems are increasing. This paper analyzes the OS dependencies of NTP and shows the OS requirements for the time synchronization. Also the implementing features of the prototype are described and the system configuration components are shown. In the outcome of the analysis, this paper shows a clock model for embedded systems.