The mineralization of the Zhilingtou Au-Ag deposit occurred in a heated circulation system of infiltratedmeteoric water during the Indosinian and early Yanshanian, at a temperature ranging from 350 to 160℃ andat a depth of less than 2 km. The ore-forming solution was acidic, strongly oxidized. and poor in sulfur, withmoderate Cl~- activity and salinity. Au and Ag migrated in the forms of AuCl_2~- and AgCl_2~-, and then wereconcentrated and precipitated in a pressure-relief, dilatant zone-a tenso-shear fracture. Pressure relief and boiling were the major mechanism for unloading of the fluid. The hydrothermal fluidwas injected intermittently, and its boiling was characterized by pulsation. The presence of high-valence man-ganese might represent the auxiliary mechanism for remobilization of Au and Ag in the Chencai Group and fortheir entering into the hydrothermal fluid.