The Hetai gold deposit is located in western Guangdong，China，belonging to a ductile shear type of gold deposit formed in an orogenic setting．Field investigation shows that the Hetai ductile shear zone has a similar attitude with the Au bearing ore veins，both steeply dipping and striking N60°~80°E，which is distinctly different from the generally N45°E striking regional shear zones．Kinematic analysis indicates that dextral shear has prevailed in both trends of shear zones. Accordingly, the Hetai shear zone is better interpreted as an extensional relay structure between two regional dextral shear zones．The inclusion temperature and phengite molecular composition from mylonites reveal shear deformation under conditions of intermediate temperature—pressure（300~500 ℃，0.4~0.6 GPa）and greenschist facies，typically suitable for Au deposition．40Ar/39Ar dating on phengite from the mylonites obtained 187~192 Ma ages，thus confining the timing of the Au deposition to the Early Jurassic，a transition period from the Indosinian to Yanshanian orogenies at the initial stages of the Pacific tectonic realm．