According to the data of average daily water level in Duchang hydrology station of Poyang lake,the paper analyzed the feature of water level variety from 1964 to 2002 and from 2003 to 2014.The results show that the lowest water level of average annual changes from significant uptrend to downtrend.The lowest water level of average years appeared 11 days ahead of time and the highest water level of that appeared delayed for 13 days; the highest level, the lowest level, multi-year average level, the highest annual average water level and the lowest annual average water level showed different degrees of decline; the water level of recession process from begin to end changes little.The duration time of recession process shortens 25 days than before and the rate of recession process is accelerated.