Abstract: The spacer grid has a great impact on convective heat transfer in rod bundles. So far, there is still no experiment data corresponding to the effect of spacer grid on heat transfer to supercritical water. Based on the convective heat transfer experiment with supercritical water in annular pipe in SJTU, the traditional correlations’ applicability was evaluated in this paper. The experiment results show that the attenuation law of heat transfer coefficient in the downstream locations is influenced by the block ratio of spacer grid greatly. Compared with subcritical pressure, the attenuation law of the downstream heat transfer coefficient has different forms at supercritical pressure.