In this paper, we propose a G-MIB (Green-oriented Information Base). This G-MIB is a MIB to collect and control information to express working status of networking equipments effectively for energy saving of the entire ICT system. We also developed a prototype system and show the results of this initial experiment of the system. Based on our experiences of standardization of Network Mobility Management Information Base (NEMO-MIB) in IETF, and research activities on Green ICT systems, we aim to standardize the G-MIB at international level. A part of this R&D has been promoted under the support of the Green ICT Innovation Promotion (PREDICT) of Ministry of Internal Affairs and Communications for the duration of 2011 to 2014.