Hydrothermal clay minerals that formed in the main metallogenic stage of the Changkeng disseminated-type gold deposit in central Guangdong were analyzed by the 40Ar/39Ar laser probe. The results give Ar-Ar isochron ages of 109.9 ± 1.4 to 110.1 ± 1.3 Ma, which are 30 to 50 Ma older than the age of silver ore bodies in the deposit. Both gold and silver mineralizations were not related to hidden granite batholith in the mining district, but probably related to evolution of sedimentary basins. This study shows that the 40Ar/39Ar laser probe is asound dating tool applicable to sediment-hosted disseminated-type gold deposit.