Extreme rainfall in raw water resource is greatly caused by climate change in Taiwan now. When typhoons are occurred, the turbidity in raw water is caused a high concentration frequently. In Taiwan the raw water, used by water treatment plants, comes from majorly river water. Most water treatment plants use chlorine disinfection; the disinfection process also produced excess disinfection by-products when raw water contains high turbidity and organic matter. In recent years, membrane method is widely being applied in water purification, but shortcomings were the higher price and not longer life. The purpose of this study is to investigate the treatment efficiency of turbidity, TOC, AOC, THMs and THMFP by using cheap nonwoven and biofilter (denoted as This System). In this study we used the base weight of 35 g/m2 nonwoven in filtration experiments for turbidity removal. Experimental results show turbidity removal by this system was nearly 90% when inlet turbidity is under moderate condition. The turbidity of treated water in effluent is all below 2 NTU that is compliance with national drinking water quality standards. Turbidity removal was about 90% using nonwoven with 21 pieces. Removal of organic matter is about 39% using biofilter when influent was in the low concentration of TOC. The removal rate is about 77% when the high TOC concentration in influent. In removal of TOC, TOC removal of raw water (I) was about 26.41%. The concentration of TOC was reduced from1169.9 £gg/L to 856.9£gg/L. The TOC removal of raw water (¢º) was about 19.65%. The concentration of TOC was reduced from 680.8£gg/L to 521£gg/L. The TOC removal of raw water (¢») was about 48.78%. The concentration of TOC was reduced from 1819 £gg/L to 936.5£gg/L. In removal of AOC, the removal rate of raw water (I) was about 50.83%. The concentration of AOC was from 59.51 £gg acetate-C/L to 28.42 £gg acetate-C/L). The removal of raw water (¢º) was about 50.97%. The concentration of AOC was from 73.08 £gg acetate-C/L to 35.8 £gg acetate-C/L. The removal of raw water (¢») was about 65.07%. The concentration of AOC was from 226.60 £gg acetate-C/L to 81.19 £gg acetate-C/L. The suggested limit level of AOC in treated water is 50£gg acetate-C/L Longer empty bed contact time of biofilter should enable the concentration below 50 £gg acetate-C/L. Removal of AOC increased with increased the empty bed contact time of biofilter . In removal of THMs and THMFP (denoted as precursors), the raw water (I) : THMs removal was about 50.22%. The concentration of THMs was reduced from 34.64 £gg/L to 17.56 £gg/L. The raw water (¢º): THMFP removal was about 46.83%. The concentration of THMs was reduced from 34.18 £gg/L to 18.27 £gg/L. The raw water (¢»): THMFP removal was about 51.81%. The concentration of THMFP was reduced from 81.49 £gg/L to 39.25 £gg/L. They were all lower than national standard of drinking water (THMs 80 £gg/L). Thus, this system can effectively remove turbidity, TOC, THMs and THMs precursors in raw water.