In order to study the purification effect of aquatic plants in the treatment of the coking wastewater, Chara sp., Nasturium officinale, Cladophora sp., Potamogeton crispus, Polygonum orientale, and Phragmites australis were, respectively, used to remove ammonia-nitrogen and COD from the coking wastewater, with the Nessler's reagent colorimetric methods and the dichromate potassium methods. The results indicate that these six kinds of aquatic plants have high removal effects for ammonia-nitrogen and COD. Their removal effects of ammonia-nitrogen and COD reach a saturation state after treating for 5 to 7 days. Then, the removal effects do not increase significantly (P > 0.05) with extending the treatment time. The best removal efficiency for the ammonia-nitrogen in the coking wastewater by using Chara sp., Nasturium officinale, Cladophora sp., Potamogeton crispus, Polygonum orientale, and Phragmites australis is 20.38%, 19.37%, 23.61%, 22.59%, 21.77%, and 32.4%, respectively. The best removal efficiency for the COD in the coking wastewater by using Chara sp., Nasturium officinale, Cladophora sp., Potamogeton crispus, Polygonum orientale, and Phragmites australis is 27.51%, 27.13%, 18.63%, 17.03%, 25.72%, and 69.04%, respectively. Compared with the other 5 kinds of plants, Phragmites australis has the highest (P < 0.05) removal effect for ammonia-nitrogen and COD.