Effects of plants on nitrogen/phosphorus removal was studied in pilot-scale in subsurface constructed wetland, the main contents included nutrient uptake、effects of harvesting and roots on hydraulic condition.The result show that the amounts of nitrogen and phosphorous removed by plant harvesting is about 5% of the total removed nutrients in SFS wetlands. The best harvesting periods is between 9~10 month every year. Plant harvesting may induce fluctuation of outflow; aboveground biomass can stabilize micro-environmental of roots. The roots can also improve hydraulic condition of SFS system, decreasing dead area 5%~10% and extending hydraulic retention time.