The purpose of this study is to propose the overall revised credits through development of credit calculation methodology for assessment issues of "Green Standard for Energy and Environmental Design(G-SEED)". The calculation method is to analyze domestic and international research data and to review the current credit and to analyze the environmental importance and cost importance through pairwise comparison of AHP analysis and construction cost analysis of certified multi-residential buildings. The survey employed the AHP method by setting up an expert group consisting of 102 experts. The increase of the building cost in Green Building is an important factor to determine whether the Green Building Certificate is necessary or not and which grade is required. There are three methodologies of credit calculation: (1) how to use the results of environmental importance and cost importance through AHP analysis, (2) how to consider the proportion in additional cost with the results of environmental importance and cost importance through AHP analysis, (3) how to add the weight to the results of AHP credits and additional construction cost. The relationship with currently assigned scores is identified through the present study while the study result will be used as a scientific and systematic basis of data for revision of the scoring systems in G-SEED.