Abstract: The rapid process of urbanization and industrialization has intensified the competition of land resources among various stakeholders.The mutual transformation between “production-living-ecological” space (PLES) has become increasingly fierce,which caused fluctuations in the quality of regional eco-environment.Taking the upper reaches of the Yangtze River (URYB) as the research object,we quantitatively analyzed the transformation of the PLES and the eco-environmental effects.Five periods of land use remote sensing monitoring data from 1980 to 2020 were used.The transfer matrix and eco-environmental quality modeling methods were applied.The results showed that: (1) During the study period,the transformation of the PLES in the URYB was characterized by the rapid expansion of living space and industrial production space,and the reduction of agricultural production space and ecological space.The main type of transformation was between production space and ecological space.(2) The eco-environment quality slightly improved.The high-value areas were mainly distributed in the eastern and southwestern parts of the URYB,while the central and western parts formed a low-value area.(3) There existed both improving and deteriorating trends in eco-environment quality.The encroachment of industrial production space and other ecological space on forest land,grassland and other ecological space was the key factor leading to the deterioration of ecological environment quality.In the future,the eco-environment and economic development policies in the URYB should take into full consideration of the transformation of the PLES,promote the rationalization of the land use structure of the PLES,and build up an ecological security barrier in the URYB.