Abstract: Experiments are performed for investigating the effect of system pressure on reflooding heat trans-fer. The test section is a rod boundle with 21 rods. The test parameter is in the range of 0.1--0.4 MPafor system pressure, 14.5--39.5mm·s~(-1) for inlet reflood flow rate, 0--0.116kW·m~(-1) for heatingpower, 380--540℃ for initial wall temperature and 25--40℃ for inlet temperature, respectively. Theexperimental results show that rewetting velocity is increased, heat transfer coefficient and guench tem-perature are all increased with system pressure.