Well-being is an area of public interests in many countries. Economy is not the only or major indicator of well-being and its focus has shifted to the overall quality and subjective feeling of life. The"National Well-being Project"has been carried out in the UK since 2010. London,as the political and economic center of the UK,is different from the rest of the UK in social,economic and demographic features. To understand the well-being in London is helpful to the improvement of decision-making process,policy impact and the quality of daily life. GLA has been trying to measure well-being in view of subjective assessment and objective indicators. The aim of the measurement is to promote the balance between economy,society,welfare and environment. The experience of well-being in London can be a reference to the Chinese society and government in transition. <<