Abstract:The project Mohole was one of the most ambitious scientific plans proposed in the late 1950s, comparable to the “Moon Landing Ambition”. It initiated and accelerated the scientific ocean drilling, through which, researchers have gradually revealed the complexity and variability of the oceanic crust after exploring the deep sea for more than half a century. One special structure as the oceanic core complex, exposed the lower crust and even mantle rocks onthe seafloor, providing a shortcut for drilling through the Moho. We here summarize the progress on oceanic crust, accretion mechanism and oceanic core complex since the initiation of the project Mohole. By analyzing the preferred sites and strategies proposed in the IODP proposals on Mohole, we aim to shortlist two possible sites for the future project Mohole in the South China Sea based on the crust characteristics. One possible site is the U1431 hole, near the relic midocean ridge in the eastern subbasin of the South China Sea. This hole has penetrated into the basalt of the oceanic crust. Thus, reentry into this hole could be taken into account in drilling through the Moho of the South China Sea. Another preferred site is the Guanshi seamount in the eastern margin of the South China Sea, where previous studies have suggested that the lower crust was probably exposed. Therefore, it could be potentially selected for multiphase drilling to penetrate into the Moho.