This study aims to analyze the factors that cause differences in the evaluation results of the life cycle carbon emissions assessment of buildings in both Korea and China as part of the methodology research of building life cycle assessment for Chinese buildings to promote building life cycle assessment in China. Specifically, it examines the building LCA standards of Korea and the standard for building carbon emission calculation in China as mentioned in the green building certification systems of both countries. Based on the investigation of the two standards, the life cycle carbon emissions of the evaluation target building were evaluated using the building life cycle assessment methods of both countries, and the influencing factors that cause differences in the life cycle carbon emission assessment results of the two countries were analyzed.