Thanks to repid progress in electronic commerce and the like on the Internet, data has been managed and autherticated using time infomation. That makes various servers to pursue time accuracy that depends on its synchronization method. NTP has been used for time synchronization at each server on the Internet, so time accuracy at NTP server has become crucial. In this report, we will describe possibility of application with more accurate time infomation and designing high-accurate NTP server that can restrain time fluctuation usually happened in conventional PCs.