In this paper the results of computer simulation of the effect of hydrothermal convection along faults, as well as the occurrences of faults, mountain relief and contrast in thermal conductivity of sedimantery basin and basement rocks as four major conditioning factors on the distribution of conductive surface heat flow in eight original and seven combined models are reported. The model designing and parameter selection are mainly based on the observed surface heat flow of conductive-convective type in some geothermal areas in the North-Central Tibet. However, the correction for convective component is not directly involved here, instead, a much profounder single-factor and multifactor model investigation is implemented. In order to reach better applicability of the simulation results a series of dimensionless parameters such as α=K1/K2 (where K1 and K2 stand for thermal conductivities of basement rocks and sedimentary basin, respectively), β=qy/q (where qy and q signify the vertical component of surf ace heat flow and basal heat flux at the bottom of the model, respectively), and r = L/H (where L and H are the distance from the left boundary of the model and height of the mountain, respectively) are adopted. The analysis of the simulation results shows that in the light of their importance the above-mentioned four factors can be arranged in the following order: convection velocity-occurrences of faults-contrast in thermal conductivities of medium-topogrphic effect.