With radiometric calibration, atmospheric correction, radiation normalization and band calculation on eight multispectral images from Landsat MSS, TM, ETM⁺ and OLI from 1973 to 2013, the area and water quality (derived from NDVI) of Lake Hongjiannao and the vegetation coverage around the lake were acquired. The study showed that the area of the lake presented a stage of shrinking trend over the past four decades. Especially, after the 1990s the rate of decline was intensified, and it totally shrank by 45.7%. Change of the NDVI values in the buffer zone that the vegetation covered around the lake were generally improved with the fluctuations. At the same time, the NDVI of water surface of the lake showed a statistically significant increasing trend, which suggested that chlorophyll-a or suspended substance was increasing and caused a degraded water quality. According to changes in lake water area, the evolution process of the lake can be divided into a stable stage (1973-1994) and a shrinking stage (1994-2013). Climate warming and drying had significant influence on change of the lake area during the stable stage. Climate change and human activities were the causes of the lake water area decrease and water quality variation. Intensive human activities, such as building reservoir, irrigation and coal mine exploitation were the dominant drivers for lake changes.