Abstract: He and Ar isotopic components of the fluid inclusions in pyrites from the main tin deposits in the central Nanling region are studied to discuss the genesis and material sources of these deposits. The results indicate that the ⁴⁰Ar/³⁶Ar ratio varies between 288 and 371 and ³He/⁴He 0.09~28.58 Ra. He and Ar concentrations change greatly in different area while ⁴⁰Ar/³⁶Ar and ³He/⁴He ratios are more consistent in the same area.⁴⁰Ar/³⁶Ar ratios are between that of the atmosphere saturation water(including meteoric precipitation and seawater)（⁴⁰Ar/³⁶Ar≈295.5）and that of Hawaii hotspot（⁴⁰Ar/³⁶Ar=350～360）; Their ³He/⁴He ratios are apparently above those of the continental crust（³He/⁴He≈0.03Ra） and are within the range of the averaged crust, of the primitive mantle（³He/⁴He≈8.57 Ra） and of the characteristic Hawaii hotspot（³He/⁴He≈27.14 Ra）. Above features indicate that the metallogenic fluids are related to the activation of the mantle plume, and they probably are the mixing product of the mantle-and crust-derived fluids and of the meteoric water. The results provide new evidences that the tin deposits are product of the crust-mantle interaction and that the mantle plumes had existed in the Nanling region.

Key words: He, Ar isotope, fluid inclusions, tin deposit, central Nanling region