Since 1998, a series of ocean scientific drilling has been carried out in the South China Sea basin, and great achievements have been made. However, the key records to uncover the opening mechanism of the South China Sea ocean floor are in the continental shelf on the northern South China Sea margin. Therefore, it is essential to carry out scientific drilling on the continental shelf. The Zhu I depression is an important tectonic unit of the Pearl River Mouth basin in the northern South China Sea margin, which has not only great potential of oil resources, but also some detailed pre- spreading records of the South China Sea ocean floor. The analysis of provenance characteristics in the shelf plays a key role in revealing the source- to- sink processes, reconstructing the tectonic evolutionary process, and predicting the distribution of high- quality reservoirs. It has always been a hot spot of current research, and can also provide a basis for demonstrating the site selection for scientific drilling in the continental shelf of the South China Sea from the perspective of sedimentology. In this paper, zircon LA- ICP- MS U- Pb dating technique, combined with zircon CL images and REE distribution characteristics, has been used to trace the source of zircon samples from typical areas on the East and west sides of the Zhu I depression, analyze the sedimentary source and sink, and discuss the structural origin of the source changes. The results show that from the early Eocene lower Wenchang Formation sedimentary period to the late Eocene upper Wenchang and lower Enping Formation sedimentary period, the material source of the depression changed from within the basin to outside the basin. Among them, the lower Enping Formation is still dominated by the supply of materials in the basin due to the lack of sedimentary strata of Wenchang Formation in some subsags of the Enping sag. The Huizhou sag and the Lufeng sag began to be supplied by off basin sources from the upper Wenchang Formation. The zircon automorphism of the Upper Eocene Enping Formation, the Oligocene Zhuhai Formation, and the lower Miocene Zhujiang Formation in Huizhou and Lufeng areas is low, the roundness is high, the edge damage is severe, the age distribution is relatively scattered, and the REE distribution characteristics are different from the basement, indicating that after the deposition of the upper Wenchang Formation- Enping Formation, the depression is mainly supplied by the South China plate outside the basin. This provenance transformation is closely related to the transformation of the rifting from south to north in the Zhu I depression at ~43 Ma.