Abstract: Aiming at the problem of the drainage ditches hardening and lacking natural purification ability, the technique of artificial plants was put forward as a solution based on the ecological sewage ditch principles. In-situ artificial plants experiment was carried out to purify the agriculture drainage in drainage ditches of the Boluo River of Dali. The results showed that the artificial aquatic plants have feasible and stable purification ability for agriculture drainage. When the COD_Mn, TN, TP and NH₃-N of the agriculture drainage were 3.8-7.3 mg/L, 1.18-2.65 mg/L, 0.05-0.19 mg/L, 0.45-0.83 mg/L, respectively, with hydraulic retention time of 2.1-2.5 h, and after the treatment of artificial grass carpet, the removal rates of COD_Mn, TN, TP and NH₃-N in farmland drainage ditches were 10.86%-40.35%, 13.04%-60.52%, 15.65%-48.68% and 13.59%-55.13%, respectively.