Spatial and temporal change study of wetland vegetation is an important part of the global change and terrestrial ecosystem research.We selected vegetation index(NDVI and EVI)data of Moderate Resolution Imaging Spectroradiometer(MODIS)during 2000 to 2015 as indicators to represent vegetation cover.Using pixel-based linear trend analysis and stability analysis method,we studied the vegetation coverage temporal and spatial evolution and vegetation stability pattern of Nansi Lake,and combined with meteorological data and other related data to analyze its control factors.The results show that:1)Vegetation coverage of Nansi Lake was controlled by landscape pattern,with a reducing banded distribution from the lake shore to the eulimnetic area.2)Vegetation coverage change had stage characters.Vegetation coverage was at a high level in growing season from 2000 to 2003,at a low level from 2004 to 2006 and fluctuated after 2006.Vegetation coverage had bimodal trends within the year,especially in the lower lake.3)Vegetation coverage decreased significantly at the lake-land ecotone in Nansi wetland.Vegetation index decreased by 0.1 to 0.3 per 10 years averagely,and it increased slightly at other regions.4)Stability of vegetation coverage presented the annular characterized,increasing from the central to shores of the lake gradually.5)Vegetation coverage has the close relationship with regional precipitation and lake level change caused by precipitation.Except the extreme precipitation year(2003),annual precipitation and wetland vegetation index showed a significant negative correlation(P<0.05),and correlation coefficients were -0.60(for NDVI)and -0.66(for EVI).As an important hydro-junction at south-to-north water transfer east route project,frequent hydrological regulation in Nansi Lake inevitably influences wetland vegetation coverage pattern,even affecting the Nansi Lake ecological processes and functions,to which relevant managers should pay serious attention.