Nitrogen removal in subsurface constructed wetland treating agriculture non-pointed wastewater was studied in pilot-scale. The experimental results showed that the removal rates of TN increases with HRT increasing. The removal rates of TN achieved 60% in macrophyte bed system when the nominal hydraulic retention time was 5 days. Removal of TN followed first-order plug flow kinetics. Rate constant of Non-plant bed, Phragmitas communis bed and Zizania caduciflora bed was 0.14, 0.26 and 0.20 d-1 respectively. Denitrification was the main removal mechanism of total nitrogen, the amount of TN that can be removed by harvesting were above 15% compared to the loading into constructed wetland system.