With industry development, global carbon emission has increased rapidly. Countries around the world have launched environmental policies related to carbon dioxide reduction. In Taiwan, the government proposed "Sustainable Energy Policy" in 2008, which clearly revealed the targets for CO¬2 reduction and milestones. Taiwan’s construction industry accounts for nearly 27.22% of total carbon dioxide emission, it’s necessary to improve and reduce the carbon emission in construction industry. In order to respond to the governmental policies, project owners will have to consider using carbon reduction materials from building’s designing stage. However, carbon reduction materials usually cost more, and the performance of how much carbon reduction can be achieved is hard to immediately evaluate, either. This study integrates energy simulation software (eQUEST) and Excel as financial software to calculate the life cycle cost and CO2 emission of construction materials, and based on carbon tax charged by different countries, the study adopts compromise decision and net present value (NPV) method to find to the best material with better carbon reduction performance and lower cost. Case study verifies it’s within 5% margin of error. In future, with more carbon reduction materials being developed and used, the integration can work with more construction materials and create in a database to facilitate the evaluation process of carbon emission.