Abstract: An analysis and some experiments of the effect of heat conduction and geo-metry on mean convective heat transfer coefficient and the maximum local heatflux have been carried out and are reported in this paper. Calculations and experiments are performed for an annular channel, consistingof a finned inner tube and a smooth outer tube, with the aid of a special deve-loped computer code CONDU. Analysis shows that heat conduction and geometry have a significant influenceon the mean convective heat transfer coefficient and the maximum heat flux.Similarity analysis shows that, in many cases of important practice applications itis necessary to introduce a correction function of conductivity and geometry. The main results of the analysis are proved by the experiments.