The purposes of this study were to investigate management status of environment-friendly features in apartment communities that were certified by Green Building Certification System (GBCS) and to suggest improvement for sustainability. A series of field investigation was conducted at ten apartment communities between July 22 and August 25, 2010. The field investigation included visual inspection and interviews with apartment managers. Among 44 GBCS certification assessment items, 17 items related with management were classified for investigation in this study. Major findings of this study are as follows: 6 features were properly used and maintained in all of the target communities. And 6 features were relatively well used and maintained, but, in some apartment communities, were found to be poorly used and maintained. On the other hand, 5 features were not or poorly used and maintained. Based on the results, the following problems were detected. In order to resolve the problem above, the managers of GBCS-certified apartment communities should make specialized efforts to properly maintain the environment-friendly features through acquiring education and information on GBCS. Also, it is suggested that housing providers including planners and designers who develop environment-friendly apartment communities consider actual use of features from users’ perspective. In addition, efforts should be made to handle potential problems with maintaining the environment-friendly features during the residents are dwelling in a GBCS-certified apartment community. Urgently, a manual that helps the manager to maintain the environment-friendly features professionally should be created and distributed. On the part of institution, the list of assessment items in the maintenance category of 「Green Building Certification System」should be revised or newly drawn up. Furthermore, the apartment management system should require that things about the environment-friendly features in case of the GBCS-certified apartment communities be included in the clause of 「the Enforcement Decree of the Housing Act」that, when the provider of an apartment community turn over the management responsibility, they should hand over documents necessary for managing the community. In addition, the provision of extending or renewing a certification after it expires should be made again. It is also necessary to introduce a follow up maintenance system which checks and assesses the use and maintenance of environment-friendly features and works. And, offering incentives should be considered as a way to spread of extending and renewing the certification and the follow up maintenance of environment-friendly features.