Optical observation is one of the most precise method for orbit determination of geosynchronous satellites. In Kashima Space Research Center of NICT, geosynchronous satellites has been monitored since 1998. Observation data tell us about the satellite population in the" overcrowded" orbit, and provide satellite orbit determinations. In the first three years, we had observed not only geosynchronous satellites but also space debris around GEO. However, due to the" light pollution" in Kashima, it was difficult to detect faint (small) objects such as space debris. Moreover, demand for optical observation of" active geosynchronous satellites" has been risen year by year. Therefore, we decided to observe mainly" active satellites" after 2000.