Because of high intense population is in Taiwan, households water use requires a considerable amount. It is substantially reduce daily water use to share primary water resources, if we can reclaim domestic wastewater properly and make it support. Currently, reclaiming water is an emerging requirement for management and application. If we can adequately monitor and treat reclaimed water, reducing environmental contaminants, costs, and environmental feedback is possible. The study treated domestic wastewater of Feng-Shan river using GAC trickling filter with two column in a series and the removal efficiency of organic carbon was observed. The experimental results indicated that removal efficiency of organic carbon concentration was decreased as the empty-bed contact time (EBCT) increased. The best average removal efficiency of TOC and DOC was about 72% and 78%. According to the TOC removal rates using GAC at different temperatures, the TOC removal rates at room temperature and 4¢Jwere respectively 95% and 90% in the first column of the experiment and 85% and 80% in the second column. The removal rates of dissolved organic carbon (DOC) using GAC folter system at room temperature and 4¢J were respectively 95% and 90% in the first column of the experiment and 90% and 87% in the second column. Obviously,the TOC removal rate treated using GAC filter system at room temperature was superior to that treated at 4¢J In comparing treated water and recycled water,most of the water quality parameters (temperature¡BSuspended solids¡BBOD¡BCOD¡BpH) were to meet recycled water quality standards.However, the system due to use GAC trickling filter system treatment that easily decrease dissolved oxygen in treated water but conductivity in treated water without changes. These two water parameters were failed to meet the recycled water standards. By the way, we found trained GAC through SEM irradiation the biofilm area of trained GAC surface at 25¢Jwas superior to that treated at 4¢J. It corresponds to the removal efficiency of organic carbon, the removal efficiency of 25¢J was higher than result of 4¢J. Therefore, a certain relationship between the biofilm area and removal efficiency of organic carbon is existed in this work.