Taking the soil and water around the Poyang Lake riparian zone as the research object, the distribution and the transport of nitrogen in the typical riparian zone of the Poyang Lake were analyzed, and the influence of purification effect of N was discussed by the principal component analysis, which were based on researching and sampling. The results show that TN mass ratio of the soil around the lake is higher than near shore and the average value of TN mass ratio is(0. 721±0. 275)mg/g. TN concentration of water around the lake is higher than near shore, and TN concentration is higher before the flood season. TN mass ratio of the soil in the beach riparian zone is decreased with the increase of the buffer width, and the value is generally lower than the embankment riparian zone. The structure of riparian zone has significant influence on the purification rate of N, and the purification effect is related to the structure and vegetation configuration.