This study was to investigate the effects of preozonation on the waterborne organic removal by the biologically active GAC fluidized bed on a laboratory scale. The raw water to be treated comes from midstream of Han river. As the ozone dose was increased in the range of $1~3{;}mgO_{3}/mgDOC$, it produced BDOC from 1.82 to 2.65 times. And BDOC formation can be expressed as [BDOC] = 0.74 + 0.21[DOC] ($R^{2}{;}={;}0.8399$). The effects of combination of ozonation followed by BACFB (Biological Activated Carbon Fluidized Bed) process were analyzed. At the ozone doze of $1~3{;}mgO_{3}/mgDOC$, the large fraction of BDOC was removed by BACFB, but parameter revealed only around 10% reduction.