Abstract: Objective Ecological carrying capacity (ECC) is crucial for evaluating high-quality development and ecosystem health within the nine provinces/regions of the Yellow River Basin. However, research on the spatial and temporal variations in ECC in these provinces remains insufficient. Methods To investigate the ECC of the nine provinces in the Yellow River Basin, an ecological carrying capacity evaluation system was established applying the Pressure-State-Response model based on the current status of resources, environment, economy and society of the Yellow River Basin. Employing a comprehensive analytical framework that integrates the combined weighting-TOPSIS model and spatial autocorrelation analysis, a systematic quantitative evaluation was conducted to delineate the spatio-temporal evolution pattern and identify the key factors influencing the ECC of the nine provinces in the Yellow River Basin from 2007 to 2021. Results 1) The ECC of the nine provinces in the Yellow River Basin has progressively increased, albeit with fluctuations, particularly exhibiting a marked acceleration after 2015, culminating in a mean value of 0.37 in 2021. 2) The ECC of Qinghai Province is significantly higher than that of the other provinces/regions, yet the differences among the provinces have been diminishing annually. 3) The spatial heterogeneity of ECC across the nine provinces is insignificant, with only Inner Mongolia and Shaanxi showing relatively large differences. 4) The obstacle degree of per capita water resources consistently remained the highest during the study period, and its constraining effect continued to strengthen, indicating that resources and environment serve as the primary impediments to the ECC of the nine provinces. Conclusions The ECC of the nine provinces/regions along the Yellow River generally showed an increasing trend but is approaching overload, with resources and environment being the main obstacles restricting ECC. This study reveals the evolution patterns and key constraints of ECC in these provinces, providing valuable insights for ECC improvement and ecological conservation strategies, aiming to foster sustainable development in the nine provinces/regions of the Yellow River Basin.