Energy cooperation system is a complex system, and its evolution process is accordance with the evolution law of complex system. In the paper, first we analyze the evolution process and the running mechanism of the typical international cooperation systems and got the inspiration to the energy cooperation in Northeast Asia, that is, economic benefits is the basis of cooperation; the evolution process is from the enterprises' cooperation to industries' cooperation and then to the nations' cooperation; we should choose technical cooperation as the breakthrough point, and cooperate within energy industry chain; at last of the paper, we designed the energy cooperation mechanism in Northeast Asia.