The convective heat transfer of supercritical-pressure RP-3 (Rocket Propellant 3) aviation kerosene in a horizon-tal circular tube has been numerically studied, focusing mainly on the non-uniform heat transfer deterioration along the circumferential direction. The goving equations of mass, momentum and energy have been solved using the pressure-based segregated solver based on the finite volume method. The re-normalization group (RNG) k-εturbulence model with an enhanced wall treatment was selected. Considering the heat conduction in the solid wall, the mechanism of heat transfer deterioration and the buoyancy effect on deteriorated heat transfer were discussed. The evolution of secondary flow was analyzed. Effects of the outer-wall heat flux, mass flux, pressure and tube thermal conductivity on heat transfer were investigated. Moreover, the buoyancy criterion and the heat transfer correlation were obtained. Results indicate that the poor flow performance of near-wall fluid causes the pseudo-film boiling, further leads to the heat transfer deterioration. The strong buoy-ancy has an effect of enhancing the heat transfer at the bottom of tube, and weakening the heat transfer at the top of tube, which results in the non-uniform inner-wall temperature and heat flux distributions. Decreasing the ratio of outer-wall heat flux and mass flux, increasing the pressure could weaken the heat transfer difference along the circumferential direction, while the effect of thermal conductivity of tube on the circumferential pa-rameters distributions is more complicated. When the buoyancy criterion of (Grq/Grth)max≤0.8 is satisfied, the effect of buoyancy could be ignored. The new correlations work well for non-uniform heat transfer predictions.