The Mu Us Desert-Loess Plateau transition zone in China, a fragile ecosystem prone to desertification, has undergone substantial ecological restoration since the early twenty-first century. This study utilized land use/cover data from 2000 to 2023 to assess the ecological response of green spaces to these efforts. A comprehensive set of ecological indices-including the green ecosystem index (GEI), equivalent ecological quality (EEQ) index, and green ecological contribution (GEC) rate-was used to quantify changes in green space extent and ecosystem quality. The study results showed a 5.83% increase in green space area, corresponding to an addition of 1979.7 km2, along with a notable rise in the GEI across 20.18% of the region, reflecting improved ecosystem function and resilience. The conversion of barren into productive green spaces has mitigated land degradation and supported ecological recovery. The EEQ of regional green spaces improved by 1.16%, and the GEC from land use changes was 1.15%. However, challenges remain, including the degradation of 3114.5 km2 of high-quality green spaces and the encroachment of 428.2 km2 by non-green land uses. Ongoing monitoring, targeted interventions, and adaptive management strategies are essential for further improving land greening and ecological quality. This study provides valuable insights for sustainable land management and ecological restoration in similar fragile environments.