[Objective] The ecological environmental changes in the headwaters of Dongjiang River in 2000—2019 were analyzed to provide scientific basis for the protection and utilization of the water source area. [Methods] Based on Landsat image data of 2000,2004,2009,2014 and 2019, four indexes including green degree (NDVI), humidity (WET), dryness (NDBSI) and heat (LST) were extracted. Principal component analysis and remote sensing ecological index (RSEI) were used. The ecological environment quality of the headwaters of Dongjiang River was evaluated and analyzed. [Results] From 2000 to 2019, the RSEI index in the study area was 0.356, 0.538, 0.332, 0.608 and 0.637, respectively. The ecological environment quality showed an upward trend, a downward trend and an upward trend. Overall, the ecological environment quality was significantly improved. The regions with better ecological environment were mainly distributed in the central and southeastern areas with higher vegetation coverage, while the regions with worse ecological environment were mainly distributed in the eastern and northwestern urban areas with close human activities. In the study area, the ecological environment quality of excellent level was dominant, and its area proportion had increased from 0.204 9% in 2000 to 92.346 4% in 2019, indicating that the ecological environment had significantly improved. The shift of gravity center of heat (LST) and dryness index (NDBSI) was 1.616 km and 1.482 km, while the shift of green density (NDVI) and moisture index (WET) was affected by population density and development degree. The distribution of green land and soil moisture began to scatter with the development of construction land, which increased the shift. [Conclusion] From 2000 to 2019, except for the deterioration of the surrounding environmental quality caused by urban transportation, the rest of the region had significant improvement compared with the previous period. The relationship between vegetation cover and urban land use was the main cause of ecological environment change in the headwaters of Dongjiang River.