Abstract: Gas sources are one of the key factors for the popularization of carbon capture and reservoir storage technology． This paper studied the economic comparison method of CO2 gas source route from the CO2 gas reservoirs，natural gas reservoirs containing CO2 and high energy-consumption enterprises as the research object． P1 ，P2 indicators and their computational models were constructed，and economic factors in the model and their calculation methods for different gas sources were elaborated． Finally，a case study of three CO2 capture demonstration projects currently running in China was conducted using the method above． The proposed method in this paper could provide great guidance on selection decisions of gas supply route for CO2-EOＲ projects