Abstract: The effect of additives on the flow boiling heat transfer in the vertical tube has been studied. Polyacrylamide (PAM) and octadecrylamine (ODA) were used as additives for enhancing heat transfer. Effects of fluid properties, concentration and molecular mass of PAM, and heat flux on flow boiling heat transfer were studied. In order to analyse the mechanism of enhancement of boiling heat transfer with additives, the diagram for binding energy was measured by XPS.The experimental results indicate that both PAM and ODA enhance the flow boiling heat transfer of water,and have an optimum range of concentration PAM can reduce the drag of flow boiling to enhance boiling heat transfer by increasing flow velocity.