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Basin-scale runoff changes reflect the comprehensive impact of various environmental variables including climate and vegetation. Among them, vegetation plays an important role in the process of runoff generation and is one of the key links affecting the hydrological cycle. However, the contribution of vegetation to runoff changes is still unclear. In order to analyze the main driving factors of runoff changes in the Yanhe River Basin, this research builds a BPG model based on the Budyko framework, Porporato model, and Guswa model to evaluate the sensitivity coefficient of runoff to vegetation change, and quantitatively reveals the contribution of vegetation to runoff change. The results showed that, the runoff in the Yanhe River Basin decreased significantly from 1982 to 2018, and a mutation point occurred in 1999. After that, the runoff decreased by 29.88% and the NDVI increased by 15.30%. In terms of the sensitivity to runoff changes, runoff is more sensitive to changes in basin characteristics including vegetation than the climate change. According to the concepts of relative contribution and absolute contribution proposed in this research, the relative contribution rate and absolute contribution rate of climate change and basin characteristic changes were − 18.13%, 117.67% and 43.22%, 56.78%, respectively. Changes in basin characteristics such as vegetation, terraces and check dams caused by human activities are the main causes for runoff changes. The relative contribution rate and absolute contribution rate of vegetation change to runoff change were 34.98% and 16.88%, respectively, which is one of the dominant factors for basin characteristics change. And basin characteristic factors such as artificial water withdrawal, terraces and silt dams are the other main contributors to runoff changes. The research results can provide a theoretical basis for guiding future ecological restoration projects and water resources planning in the basin. • BPG model was built to evaluate the sensitivity and quantitatively reveal the contribution of vegetation to runoff change. • Proposed the concepts of relative contribution and absolute contribution of runoff change. • The runoff was more sensitive to basin characteristics change than climate change. • Climate change led to runoff increase while basin characteristics change led to runoff reduction in Yanhe River. • Changes in basin characteristics such as vegetation are the dominant factors of runoff changes. [ABSTRACT FROM AUTHOR]