The year of 2009 was crucial for the EU’s policy in response to climate change. The EU put forward a climate adaptation strategy which expands its climate policy to a bi-pillar institutional system covering both mitigation and adaptation. In the respect of climate diplomacy，in order to reach a consensus on the UN’s institutional framework for countering climate change after 2012，the EU proposed “a comprehensive agreement on climate change in Copenhagen”，in which the EU fully expounded its vision and ideas for global cooperation on climate change at the next stage. All the above efforts indicated that the EU has become initially mature in its climate strategy aimed at protecting environment，achieving sustainable development and upgrading competitiveness，as well as promoting its international influence. However，to achieve the abovementioned objectives，the EU is supposed to face not only the tests of international variables，but the internal disputes between various interests.