The regression formula between 3He/4He ratio of underground fluids and terrestrial heat flow in continental areas is tested by data sets from the former Soviet Union and the mainland of China. The results show that there is no close relation between the two values. The heat-He relation might estimate the regional heat flow value with ±25% accuracy at best. We propose that the ratio of crust/mantle component of continental heat flow (qc/qm) be inversely related to the 3He/4He ratio of underground fluids. Based on data sets of 3He/4He ratio and qc/qm in the Eurasia and Canadian Shield, we obtain the regression relation between qc/qm and 3He/4He: qc/qm = 0.815-0.300*loge(3He/4He), in which the unit of 3He/4He is Ra (atmospheric 3He/4He ratio). The crust and mantle heat flow components can be taken from surface heat flow and qc/qm ratio. Based on this formula and heat flow data in major basins of China, the crustal, mantle heat flow values and the average crustal heat production rates were estimated. The
