Nuclear safety is getting more important in response to the Fukushima Danchi nuclear disaster in 2011 It is also the fact that designers put emphasis on economic efficiency Accurate prediction of fuel surface temperature is important from these points of view In this study a method to predict heated surface temperature was developed by modeling heated sections as upward flow in a vertical circular tube under high-pressure conditions of 7[MPa] and tracking the changes in flow regime as nucleate boiling, dryout and post-dryout The results were compared with several experimental data It was found from the comparison that prediction performance of boiling transition points and heated surface temperature of pre- and post-dryout region was good