Abstract: A new model of the property allocation for carbon emissions in power system is proposed. Based on the structure decomposition of carbon emission in power systems, carbon emissions of power system and related electricity consumers are divided into such 3 parts as carbon emissions of integrated electricity load, net loss and auxiliary power by using the load analysis theory. After determining the structure composition and its corresponding calculation indicators of the carbon emission flow in power system, the composition distribution of carbon emission flow is calculated. Then the power flow tracing method is used to allocate and quantify the carbon emission caused by net loss. In the end, the real-time allocation result of carbon emission on property rights is obtained. Simulation of IEEE 14-bus 5-machine system is performed, and the results show that the proposed model is feasible and correct.