Inner Mongolia serves as a crucial ecological security barrier for northern China. Examining the spatial and temporal evolution of ecological environment quality， along with the zoning for ecological management， is crucial for enhancing the management and development of ecological environments. Based on the Google Earth Engine cloud platform， four indicators-heat， greenness， dryness， and wetness-were extracted from MODIS remote sensing image data spanning 2000 to 2023. The remote sensing ecological index （RESI） model was constructed using principal component analysis. By combining the coefficient of variation （CV）， Sen + Mann-Kendall， and Hurst indices， the spatial and temporal variations and future trends of ecological environmental quality of the Inner Mongolia were analyzed. The influencing mechanisms were explored using a geographical detector， and the quadrant method was employed for ecological management zoning based on the intensity of human activities and the quality of the ecological environment. The results indicated that： ① The ecological environment quality of Inner Mongolia from 2000 to 2023 was mainly characterized as poor to average， with a spatial trend of decreasing quality from east to west. From 2000 to 2005， Inner Mongolia experienced environmental degradation， followed by a gradual improvement in ecological environment quality. ② Inner Mongolia exhibited the largest area of non-significantly improved and non-significantly degraded regions， and the overall environmental quality was more stable. However， ecosystems in the western region were more fragile and prone to fluctuations. The area of sustained degradation versus sustained improvement in the future trend of change was larger， and the western region is expected to be the main area of improvement in the future. ③ The results of single-factor detection showed that the influences on RSEI values were， in descending order， precipitation， soil type， land use type， air temperature， vegetation type， elevation， population density， GDP， and nighttime lighting； the interactions among driving factors on RSEI changes showed a bivariate or nonlinear enhancement， which suggests that the interactions of each driving factor could improve the explanatory power of spatial variations in ecological environment quality. ④ Based on the coupling of human activity intensity and ecological environment quality， the 12 league cities of Inner Mongolia were divided into ecological development coordination zones， ecological development reserves， and ecological development risk zones. This study can provide a scientific basis for ecological environmental protection and sustainable development in Inner Mongolia.