With an awareness of the fact that influence of building industry on the environment problems is great, many countries have been endeavoring to construct sustainable and environmentally-friendly buildings. In Korea, the GBCS (Green Building Certification System) has been in force since 2002. Total 6 types of buildings are dealt in the GBCS. Especially, it is expected that the number of apartment complexes, which are the most common type of residences in Korea, applying for GBCS has increased continuously. In this study, we aim to pick out the items requiring improvement for the green apartment complex. Existing 12 certified apartment complexes were selected. GBCS assessment results and actual conditions of design and construction were investigated and analyzed. Total 18 items requiring improvement were picked out in accordance with the average score-to-allotted point ratio. Relevant particulars expected to be helpful for the next design works were also presented.