Abstract: As an important part of ecological barrier in the upper reaches of the Yangtze River,Le'an Wetland was the key area of ecological development in the Daliang Mountain.It was also a typical ecosystem of plateau wetlands at elevation 2500~3000m.The vegetation cover (the ratio of vertical projection area of vegetation to unit area) was an important ecological parameter to reflect the growth status of wetland plants.It played an important role in the assessment and monitoring of the wetland ecological environment.Based on the data of MODIS normalized vegetation index in 2011-2015 years,the vegetation cover and its changing trend of Bhutto Le'an Wetland Reserve were estimated by using the two sub-pixel model.And the change of vegetation cover in Le'an Wetland Reserve was analyzed in order to provide scientific basis for ecological environment evaluation and management in protected areas.The results showed that the vegetation cover of Le'an Wetland Reserve was in good condition,and the proportion of vegetation covering area in moderate and above grade was more than 50%.During the 5 years,the vegetation coverage of protected areas showed a stable state in general,but the change trend of vegetation cover was different at different levels and different periods.The vegetation cover in space presented a descending trend from Wandun Mountain-Sike Township to their two sides.Compared with Ruoergai wetland at about 3500m above sea level,the distribution of vegetation cover in Le'an wetland was mainly affected by topography,hydrothermal conditions and human activity factors.