As an essential component of the continental crust, the products and magmatic systems of silicic volcanic activity recorded the vital information on the continental crust differentiation. Intensive Cretaceous volcanism was widespread along the coastal area of SE China, dominated by rhyodacites and rhyolites, offering a unique opportunity to unravel the growth and evolution of transcrustal magmatic systems. Here we present systematic zircon Hf isotopic data integrated with previous researches for the Changyu caldera in eastern Zhejiang Province, in order to constrain the magma sources and evolution of the magmatic system. The different eruption stages of the caldera, including caldera- forming eruptions, post- caldera eruptions and the rhyolite domes show consistent zircon Hf isotopic compositions with εHf(t) values of 7.4 to0.2 and TDMC Hf model ages of 1.45 Ga to 1.04 Ga, suggesting the genetic link of the volcanic rocks of different eruption stages and that the magmas were mainly formed by the mixing of depleted mantle- derived magma and magma derived from ancient crust of the Cathaysia block. The compiled zircon Hf isotope data of the Late Jurassic to Cretaceous volcanic rocks from the coastal SE China reveal that their εHf(t) values are typically located far below the depleted- mantle evolution trend with a particularly wide range, and their TDMC Hf model ages cluster mainly between 1.8 and 1.0 Ga almost without Archean ages. This implies that the ancient crustal basements of the Cathaysia block should also be prevalent beneath the volcanic field east of the Zhenghe- Dapu fault, besides the sporadic outcrops of the Precambrian basement rock, and that the ancient crust materials were involved to varying degrees in the origin of volcanic magmas along the coastal SE China. Furthermore, the generation of high- silica rhyolitic magmas from the Changyu caldera and other Cretaceous calderas in the coastal SE China reflects the long- term evolution of the transcrustal magmatic system as well as crystal- melt segregation processes. Juvenile mantle- derived magmas not only contribute to the genesis of silicic magmas and the growth of continental crust, but also supply the necessary magma and heat flux for the transcrustal magmatic system of the large- scale silicic volcanism. The internal and external structures of calderas, the comprehensive mapping on genetic types, spatiotemporal distributions, as well as the volcanic eruption history are the crucial foundations and important contents of future studies on the transcrustal magmatic systems of the intensive Cretaceous volcanism in the coastal area of SE China.