Abstract: Purification of eutrophicated water was accomplished by palm fiber. Six groups were set up with a repetition in each group，which were 12 water tanks including a control group without palm fiber. Sampling taken every 5 days were determined for the content of TN, TP, NO-2-N, NO-3-N, NH+4-N, CODCr and DO and so on. The results of experiment show that palm fiber has good effect to purify TN, TP and CODCr; The groups of spring and summer have better effect than that of autumn and winter；the test group of palm fiber were much better than that of controls. There is obvious difference of purification effect between groups with different density of palm fiber emplacement: the bigger density of that emplacement, the better purifying effect.But there is unobvious effect of NH+4-N purification by palm fiber and its different emplacement compared with control group. The content of NO-3-N decreased in all groups with palm fiber and it has good purification effect by high density of emplacement. Therefore, the palm fiber is an ideal natural material for eutrophication water purification.