A multi-layered waterproofing membrane system with thermal reflection-insulation performance was developed and its insulation performance was evaluated experimentally. The thermal insulating performance of this system was obtained by the following measurement parameters in outdoor exposure test and artificial indoor test; the specimen size-effect, the difference of exposed concrete substrate and the types of waterproofing membrane. As a result, the temperature amplitude in testing chamber is lower than the traditional membrane system and this system had high thermal insulating performance in summer season or high temperature. Then, the thermal conduction performance of this system was measured by the artificial temperature cyclic test in order to evaluate its performance conveniently and its result showed good correlation with outdoor test result. Therefore, it is expected that the thermal insulation performance of various waterproofing membrane system can analyze by this simple test method and propose green roof effectively.