Abstract: Experimental and analytical investigation was carried out in this study to show the effect of surface tension on the heat transfer coefficient of gases flow inside micropipe heat exchangers during condensation process. Analytical empirical correlation was formulated for the convectional heat transfer coefficient of two phase flow inside micropipe heat exchangers. Carbon dioxide (CO2) was used as working fluid. A comparison between experimental results and that obtained by developed correlation were carried out and a comparison between these results and literature published correlations were carried out too. The results of this research showed that the predicted heat transfer coefficient of the proposed correlation was more closely for experimental results than other correlations results, this is because of considering of the surface tension.