Global warming has triggered public concern for environmental protection. Given this trend, carbon emission evaluation and improvement become a critical management in many companies. However, the developing of such kind of a model is very complicated, considering regulations, process, and platform to register and many other problems managers have to deal with. The complex process makes carbon emission management a very difficult issue. This research is to integrate green design and life cycle assessment (LCA) and builds up a feasible model- low carbon value chain model (LCVCM)- for assessing and improving carbon emission on a case product. The implementation method involves four steps: "Scoping the process of product", "Analyzing carbon emission on each process", "Simulating carbon Impact", and "Targeting and Improving the Product". From the result, the carbon footprints are significantly reduced. LCVCM drives an original product from a less green into a greener and more eco-efficient product. After years of efforts, the standard quantity of carbon emission will be clearly taken into consideration by green product development. This model is created which enabling many organizations to improve their carbon emissions. It also supports organizations to find the balance between environment and economics thereafter.