Abstract: In order to explore the coordination relationship between urbanization quality and scale of Lanxi City cluster in the upper reaches of the Yellow River, This paper established the evaluation index system of urbanization quality and urbanization scale and employed the coupling coordination degree model to measure the coupling coordination degree of the quality and scale of urbanization in nine cities (prefectures) of the Lanxi urban agglomeration from 2013 to 2023. The results indicated that: (1) Regarding the dynamic changes, the quality and scale of urbanization in the Lanxi urban agglomeration upstream of the Yellow River exhibited wave-like development characteristics and had undergone three processes: “growth period” , “pain period” and “reform period” . (2) From the spatial differentiation perspective, the urbanization quality level of cities (prefectures) in the Lanxi urban agglomeration generally presented a “dual-core” model, and the polarization effect was remarkable, which was specifically manifested as a “hammer spinning” structure with small sizes at both ends and a large size in the middle. (3) Lanzhou and Xining were the high-level coordinated cities of Lanxi City group. The development of the eastern city cluster was relatively good, and the low-level coordinated cities were mainly located in the southwest of the city group. The authors proposed that the differentiation strategy ought to be implemented, regional cooperation relations should be constantly strengthened, the public affairs coordination governance mechanism should be established in Lanxi City Cluster, public service co-construction and sharing should be further promoted, and policy guidance and supervision should be enhanced.