The thermal characteristics of the low-density ablator are quantified by conducting the heating tests of materials in an arcjet wind tunnel. In the tests, test pieces of the ablator with a diameter of 40 mm and a length of 58 mm are put into arcjet flow. The arcjet wind tunnel is run for two sets of operational condition: a low heating condition for the heat flux of 0.97 MW/m² and the impact pressure of 1.93 kPa, and a high heating one for 1.97 MW/m² and 4.25 kPa, respectively. The surface temperature and in-depth temperature are measured during the testing. The surface shape changes of ablator and the amount of mass loss of ablator are measured after the heating tests. The obtained experimental data are analyzed by using an integrated computational method developed earlier. Agreement between the calculations and the heating tests are excellent in the comparison of the surface shape changes of ablative test pieces. The temporal variations of surface temperature are also well reproduced by the present numerical method within the experimental error. However, the calculation underestimates the in-depth temperatures and the amount of mass loss of ablative test piece. The reason for this discrepancy may come from the lack of the thermal conductivity data especially in high temperature range above 500K. In addition, the present study suggests that the thermal conduction of the ablative test piece used in this study could be anisotropic to some extent.