Based on an analysis of terrestrial heat flow, rock thermal conductivity at different depths, radioactive heat generation and radioactive depth variable constant, the authors estimated the terrestrial temperature at different depths by calculating the measured temperatures from shallow strata to the depth of the crust. Then the hot dry rock resource amount at the depth of 3 000~10 000 m was estimated by virtue of the volume method. The results show that the resource amount at the depth of 3 000~10 000 m could reach 2.5×1025 J, which is equivalent to the heat of 860 trillion tons of standard coal. This resource is estimated to be 5 200 times that of the current total energy consumption on the basis of 2% of the exploitable resources amount.hemas-microsoft-com:office:office" />