Climate change is causing negative impacts on all countries and their production activities.  Mekong River basin is ranked as one of the most vulnerable regions under climate change. To adapt with climate change, Mekong countries have built their national policy strategies and action plans. In addition, some climate change response initiatives have been introduced and implemented at sub-regional level. This short paper reviews climate change impacts and responding policies of the Mekong countries. It uses data, maps, schemes and reports published by different sources for the analysis. All these information is systematized from Langcang upstream (Yunnan China, Myanmar) to mid-and-downstream (Thailand, Laos, Cambodia and Vietnam Mekong Delta). The paper also analyzes and discusses some challenges in the climate change policy implementation in the Mekong region.