The western Borneo (Indonesia) was located at the intersection of the Tethys and Paleo-Pacific tectonic domains during the Mesozoic, and is a unique tectonic unit in the world where multiple plate dynamics systems were superimposed sequentially and simultaneously. Therefore, the study of the petrogenesis and tectonic setting of granitoids in this region is crucial to reveal the tectonic-magmatic evolutionary history of Southeast Asia and the magmatic evolutionary mechanism under the superposition of multiple tectonic systems of orogeny.In this study, zircon U- Pb chronology, geochemistry, and Sr-Nd-Hf isotope analyses of granitoids from the Mensibau batholith in West Borneo were carried out. The LA-ICP-MS zircon U- Pb isotopic ages of 126. 9 ± 2. 1 Ma and 141. 8 ± 2. 6 Ma for quartz monzonite and K-feldspar granite sample, respectively, indicate that the rocks formed in the Early Cretaceous and magmatism lasted at least 15 Ma. The Mensibau granitoids has high SiO2(67. 5%~73. 3%), high K2O (4. 3%~5. 4%) and low P2O5 (0. 07%~0. 14%) content, aluminum saturation index (A/CNK) of 0. 92~1. 06, and the presence of hornblende, belongs to the metaluminous-weakly peraluminous I type granites. These granitoids are characterized by enrichment of light rare earth elements (LREEs) and depleted of heavy rare earth elements (HREEs), weak negative europium anomalies (δEu = 0. 65 ~ 1. 00), and enrichment of large ion lithophile elements (Rb, Th, U, and K) and depleted of high field strength elements (Nb, Ta, and Ti), showing the typical geochemical characteristics of island arc granites. In addition, the Mensibau granitoids has positive εNd(t) values (+3. 14~+4. 09), low \[n(87Sr)/n(86Sr)\]i values (0. 70420~0. 70424), and high zircon Hf(t) values (+9. 30~+13. 87), indicating that the magma was derived from partial melting of the juvenile mafic crust.A comprehensive regional geological background study indicates that the Mensibau granitoids developed on subduction-accretionary complexs may be accretionary arc magmatism of juvenile crustal origin under the superimposed subduction of two tectonic regimes (Paleo-Pacific and Neo-Tethys Ocean), confirming that the West Borneo region experienced significant accretionary orogeny during the Early Cretaceous.