| Now, economic efficiency is more and more considered by antitrust authorities and courts in merger cases in order to decide whether allow the mergers which have anti-competitive effects. At the same time, efficiency has become the target of competition policies in many countries.Mergers may have anti-competitive effects but they can also generate efficiency gains. Building efficiency defenses system reasonably, plays an important role for antitrust authorities to accurately measure the foregoing both sides which the merger brings and effectively make the decision whether the merger is allowed. This paper bagins with cost-benefit analysis, aims at immature places of merger control in China, analysises the importance and feasibility of efficiency defense system in merger control, references the current standards existing in theory and practice, learns from foreign experience and development trends, and makes suggestions on building efficiency defense system which lines with national conditions. |