For building the ecological engineering to purify the eutrophic water, six economic plants,which are Cress,Ipomoea aqutica,leek,Chinese chives,Celery and Hemerocallis respectively,were selected,and the purification ability and the bio-ecological character of them were studied.Results show that each species has great ability to removal total nitrogen(TN) and total phosphorous(TP),especial Cress and Ipomoea aqutica,during the 20 d experiment period,the removal percentage to TN and TP is 89.5% and 98.2%,respectively;TN concentration in water declined in negative exponent form with the time continuing.The changes of Chla,BOD5 and COD were observed?during the treatment.It was found that in high nitrogen eutrophic water,except Cress and Ipomoea aqutica,the Chla,BOD5 and COD decreased with time continuing,but the acrid smell in the water aggravated during leek and Chinese chives treatment.The integrated analysis of all indices indicate that in different nitrogen eutrophic water,the purification effect of Ipomaces aquatica was the best,Cress take second place,Hemerocallis and Celery place in the center,leek was worst.