Abstract: Lake water level is a significant factors which essentially affects normal ecological function of lake. Proceeding researches and investigations specifically on characteristics of lake ecological water level alteration is prerequisite and imperative for enhancing understanding and comprehending about how lake water resources system changes during decades periods. Based on daily water level from year 1960 to year 2014 which acquired from monitoring data of 5 hydrological stations distributed over the region of Poyang Lake from 1960 to 2014, this current study first analyzed characteristics of inter-annual variation of Poyang Lake water level in recent years. On this basis then the IHA/RVA method was applied in this research to quantitative degree of ecological water level alteration and its corresponding spatial from time period of 2000-2014. Result shows that water level of the Poyang Lake has declined and recessed evidently in recent years. Specifically the annual average water level of Hukou, Xingzi and Duchang stations shares highly consistent and conformant alteration tendency, without apparent water level changes since 2009, and water level variation among those three stations has almost vanished from graph. In general speculate ecological water level variation of Poyang Lake during 2000-2014 is comparatively moderate which amounts to 38.86%.Among those 5 hydrological stations, Duchang station enjoys the highest changing, followed by Xingzi, Hukou, Kangshan and Tangyin station descendingly. Furthermore the variability of 5 major hydrological indicators which includes monthly water level (June and November), minimum 3 days and 30 days average water level, time of highest annual water level, frequency of high water level as well as annual water level reduction rate are all amount to over 50%. It is revealed that water level anomaly of Poyang Lake and its spatial variability during recent years may closely related to lake bottom morphology and topography alteration caused by sand mining. From those above analyses it is certainly illustrated that the current hydrological variation and alteration of Poyang Lake has already caused multiple adverse effects.