Abstract: In this paper, the root, stem, and leaf samples were collected from six herb species (Artemisia selengensis, Potentilla cryptotaeniae, Impatiens nolitangere, Artemisia capillaries, Bidens biternata, and Polygonum persicaria) in the riparian zone at the upstream of Hunhe River in July, August, and September, 2010, aimed to compare the total nitrogen (TN) and total phosphorus (TP) contents in the organs of these herb species. In the test organs, the TN and TP contents were 5.10-45.06 mg·g^-1 and 1.60-18.01 mg·g^-1, respectively, and the N/P ratio ranged from 0.92 to 6.14, with an average of 2.68. There existed significant differences in the N and P contents between different organs of the same or different herb species. Among the test five species, I. nolitangere had the highest TN and TP contents, being able to be selected as a candidate species used for the improvement of water quality in the riparian zone of Hunhe River.

Key words: restoration wetland, nitrous oxide (N₂O), nitrification-denitrification, exogenous nitrogen, Yellow River estuary.