Abstract: Taking Xinmin City of Liaoning Province as the research object, based on the Landsat 8 OLI_TRIS data of similar months （May to June） in 2014, 2017 and 2020, four ecological factors [greenness （NDVI）, humidity （WET）, dryness （NDBSI）, heat （LST）] were extracted, and the remote sensing ecological index （RSEI） was constructed by principal component analysis to evaluate the spatial and temporal evolution characteristics of eco-environment quality in the study area. The results showed that the regional mean values of RSEI in Xinmin City in 2014, 2017 and 2020 were 0.397, 0.348 and 0.506 respectively, showing a trend of first decreasing and then increasing. From 2014 to 2020, the areas with poor eco-environmental quality and relatively poor eco-environmental quality were mainly distributed in the northwest region, and the area ratio decreased from 62.5% to 33.2%. The areas with relatively good eco-environmental quality and good eco-environmental quality were mainly distributed in the southeast, and the proportion of area showed an obvious trend of first decreasing and then increasing, from 21.3% to 18.4% and then rising to 37.0%. Among the four factors, greenness and humidity played a positive role in the quality of eco-enviroment, and the positive effect of humidity was generally more significant; dryness and heat played a negative role, and the negative effect of dryness was more significant.

Key words: eco-environmental quality, Landsat 8 OLI_TRIS, remote sensing ecological index, principal component analysis, Xinmin City