Pilot scale sewage sludge ecological stabilization system was conducted for sludge dewatering,mineralization and stabilization.The study was performed from 2005 to 2008 on a bed with a total area of 80 m 2.Influent total solid,volatile solid and water content were averaged 22.34 g/L,7.76 g/L and 97%.Sludge loading rate was averaged 0.691 kg(TS)/m 2·d.The first two years were sludge loading period and the other two years were natural stabilization period.The percolate COD removals ranged from 60%~80% in the first year,and from 40%~50% in the second year,with 100~200 mg/L of effluent COD concentration.During the first two years,the percolate did not filtrate downwards evenly.Part of percolate filtrated downwards along stems,roots and cracks existing in dried sludge which had lower flow resistance.During the natural stabilization periods,sludge water contents decreased to 34.3% and 30.5%,and organic matter contents decreased to 16.8% and 10.24% in the third and forth years,individually.Total nitrogen and total phosphorus contents of stabilized sludge were averaged to 0.98% and 0.27%.It was found that plant biomass and nutrient components in the system were higher than that of native ones.