Abstract: Effect factors of decolorization in singlestep decolorization and defluorinate technology of wetprocess phosphoric acid (WPA) by using activated carbon and sodium carbonate as depigmenting agent and defluorination agent respectively were studied.Take Gore membrane as filter medium,the best technological conditions of decolorization were drawn on the basis of experiments:reaction temperature was 70 ℃,reaction time was 70 min,dosage of sodium carbonate was 22 g/L,dosage of activated carbon was 6 g/L and sedimentation time was 1 d.Under these conditions,decolorization rate of WPA could reach above 80%.<BR>