It is one of key issues to predict a critical heat flux (CHF) with the highly subcooled flow boiling and the CHF margin for the promising design of plasma facing components for the next generation fusion machines such as an International Thermonuclear Experimental Reactor and a Fusion Experimental Reactor. In particular, divertor plate is subjected to severe heat loads under a condition for one side heating. Because of no correlations predicting CHF for the highly subcooled flow region with heating on one side of the divertor plate, experimental data which were obtained under one sided heating condition have been evaluated by various existing CHF correlations which are based on a condition for uniform circumferential heating. As results, experimental CHF data of the straight tube are relatively good agreement with some correlations within an accuracy of −20 to +10 %, but no correlations are available in the CHF prediction of the externally-finned tube. Further experiments are necessary to evaluate the applicability of the existing CHF correlations under a condition for one side heating.