With gas chromatography-mass spectrometry, high performance liquid chromatography analytic methods, it was proved that the ortho-hydroxylation medial product was produced mainly from the aerobic biodegradation of fluorophenols. The influence of different pH value on the ortho-hydroxylation products was studied. With increasing of pH value the ratio of C2 ortho-hydroxylation to C6 ortho-hydroxylation increased gradually; and no C6 ortho-hydroxylation was examined and measured at pH 7.5.