Abstract: The southwestern part of the South China Sea (SCS) is one of the most complex tectonic regions of SCS. To further understand the tectonic evolution of the Malay Basin and the southwestern part of the SCS, we systematically rebuilt the tectonic subsidence history for 69 representative pseudo-wells based on recently published seismic and drilling data. Results show that the Cenozoic tectonic subsidence history could be divided into four stages including syn-rift rapid subsidence stage, early post-rift anomalous and rapid subsidence stage, middle post-rift slow subsidence stage, and late post-rift slow subsidence stage. Further analyses suggest that the Malay Basin is a rifted basin and later was superimposed by small-scale strike-slip action in its wings. The anomalous rapid tectonic subsidence in the early post-rift stage might be resulted from inelastic yield of the lithosphere caused by sedimentary loading.