The building embodied stage is the LCA research focus due to large and intensive CO2 emissions. In order to establish the CO2 emissions calculating model during the embodied stage, CO2 emissions load in the process of building materials, equipments manufacturing, transporting and construction should be included. CO2 emissions during building embodied stage of 78 office buildings were analyzed by this model. On average, the amount of carbon emission during embodied stage is 326.75 kg/m 2. The carbon emission in per unit area increase with the growth of building height and that of super high-rise buildings is 1.5 times as much as multi-story buildings. Carbon emission of civil work accounted for about 75% of the total amount during embodied stage, and the carbon emissions of rebar, concrete, mortar and wall materials accounted for over 80% of the carbon emission of civil work. According to the statistic of prediction model dependent on building story and amount of building materials,the CO2 emissions during building embodied stage could be precisely predicted on basis of the independent variablesincluding concrete and wall materials respectively.