[Objective] The eco-environmental effects and spatial differentiation mechanism of the transformation of productional-living-ecological space were determined, in order to provide a scientific basis for coordinating the efficient use of land and the sustainable development of social ecology. [Methods] Taking the upper reaches of the Yangtze River as the research object, a land use transfer matrix and eco-environmental quality index were used to quantitatively analyze the spatial differentiation characteristics of the productional-living-ecological space transfer law and the eco-environmental effects in the upper reaches of the Yangtze River from 1990 to 2020. The geographical detector model was used to identify the driving factors of spatial differentiation of eco-environmental quality. [Results] ① The productional-living-ecological space pattern in the upper reaches of the Yangtze River was significantly different, and the ecological space was widely distributed in the western and southern regions of the basin. The production space was mainly concentrated in the Chengdu Plain and the intermountain basins scattered in the dense river network that was conducive to farming. The living space was scattered in the central cities such as Kunming, Chengdu, and Chongqing. ② The eco-environmental quality was generally stable and dominated by high quality. The spatial pattern of ecological environmental quality was lower in the central regions and higher in the surrounding areas. The low quality areas were distributed in clumps and strips in the Sichuan Basin and the north side of the Hengduan Mountains. The medium and high quality areas were mainly distributed in the periphery, southwest, and south portions of the upper reaches of the Yangtze River. ③ The conversion of agricultural production space into forest land production space and water ecological space, and the conversion of grassland ecological space into forest land ecological space were the main land conversion types that promoted the improvement of eco-environmental quality. In contrast, the deterioration of eco-environmental quality was closely related to the transformation of forest ecological space into agricultural production space, grassland ecological space, and industrial production space. ④ Topographic relief, slope, population density, and land use intensity were the main driving factors affecting the spatial differentiation of eco-environmental quality. The interaction between natural factors and social factors affected the eco-environmental quality in the upper reaches of the Yangtze River. [Conclusion] The eco-environmental quality of the upper reaches of the Yangtze River remains relatively stabilized in general, but the trends of local ecological deterioration should not be ignored. With regard to future policy formulation, the land use structure of the productional-living-ecological space should be optimized according to the natural conditions of each region, the main function positioning, the actual situation of the eco-environment, etc.