Abstract From the geological-geochemical features of the Huashan-Guposhan Granite Batholiths, the depth of emplacement (5.5km ), the temperature of country rocks (196℃) and initial temperature of granite melt (950℃ ) during its emplacement are obtained. With these parameters a mathematic model calculating for the emplacement age of the Huashan-Guposhan Granite Batholiths is established in this paper. Model calculation results suggest that the cooling time (Δtcol ) for the Huashan-Guposhan Granite Batholiths from initial temperature to crystallization temperature were 4.14 Ma and 4.36Ma respectively, the prolongation time (ΔtL ) caused by latent heat generated from crystallization were 2.67 Ma and 2.81Ma respectively. Since the radioactive elements of the Huashan-Guposhan Granite Batholiths (U—13.52×10-6，Th—56.1×10-6，K2O—5.79%( Huashan); U—13.7×10-6，Th—52.4×10-6，K2O—5.28%( Guposhan) ) are as high as 2~3 times of those of the world average granites (U—5×10-6，Th—20×10-6，K2O—2.66%) , the prolongation time (ΔtA ) caused by radiogenic heat from the decay of the radioactive elements were 37.35 Ma and 45.1Ma, which are much longer than theΔtA value calculated for radioactive elements of the world average granites (3.17 Ma, Huashan ). Therefore, the time elapsed from the magma emplacement to the crystallization-solidification (△tECTD ), which should be the sum ofΔtcol , ΔtL, andΔtA, are 44.16Ma and 52.27Ma for the Huashan-Guposhan Granite Batholiths. In combination with zircon U-Pb isotopic ages (162Ma and 163Ma) representing the crystallization age, the emplacement ages of the Huashan-Guposhan Granite Batholiths are estimated to be 206.16.Ma and 215.27 respectively. These suggest that the emplacement of the Huashan-Guposhan granite magma was in the Indo-Sinian Period.