To better understand the impact of the rivers of Ganjiang and Xiuhe on the water levels of the lakes of Dahuchi and Shahu in the Poyang Lake National Nature Reserve, the characteristics of the water level of the Xiuhe River and the variation trend were analyzed based on the measured water level at Wucheng Station on the Xiuhe River from 1953 to 2010. The results indicates that (1) the water level variation at the Wucheng Station show the characteristics of "single peak", the annual water level variation is stable in the scale of 58 years, the highest level often appear in June, July, August or September while the lowest level appear in December, January, Feboray or March; (2) The difference of water level between the Xiuhe River, Dahuchi Lake and Shahue Lakes are 5.43m and 5.30m respectively. The Dahuchi Lake will get in connection with the Xiuhe River when the water level at the Wucheng Station is higher than 16.11 m, and the Shahu Lake will get in connection with the Xiuhe River when the water level get over 16.45 m.