A building energy performance certification and disclosure system aims to increase the market value of energy efficient building and to induce energy efficient investments by making owner disclose building energy performance during building transaction. This policy has been widely adopted in many countries worldwide, and also enforced in Korea from February 2013. The purpose of this study is to suggest strategies to improve operational rating method in building energy performance disclosure system and to discuss a few requirements to be considered in developing operational rating method. Operational rating methods of Display Energy Certificate, Energy Star Portfolio Manager, Energideklaration, and Nabers energy rating were investigated and analyzed. Grading criteria and performance index, energy benchmarks, and energy normalization methods should be developed to improve the operational rating method.