Abstract: Melaleuca alternifolia is a fast-growing woody plant and produces tea tree oil, a commodity in demand by the health-care industry. The purifying effect of M. alternifolia grown in floating-bed systems to domestic wastewater was investigated, and compared with the Cyperus alternifolius grown in floating-bed systems. Results indicated that M. alternifolia floating-bed was capable of removing pollutants from domestic sewage. M. alternifolia floating-bed maintained high purifying effect from August to December, average removal rates of TN, TP, BOD5, CODCr, NH4-N and NO3-N were 71.39%, 83.32%, 84.96%, 69.91%, 72.53% and 76.23%, and accounted for 87.55%, 95.03%, 97.48%, 98.24%, 88.73% and 89.37% of removal rates for C. alternifolius floating-bed, respectively. However, M. alternifolia had low purifying effect in January, removal rates of TN, TP, BOD5, CODCr, NH4-N and NO3-N were 29.83%, 61.33%,70.53%, 49.89%, 39.03% and 53.84%, and accounted for 38.67%, 68.24%, 86.77%, 77.70%, 64.20% and 65.87% of removal rates for C. alternifolius floating-bed, respectively.