With increasing attentions on energy and global change issues,carbon emission from urban residents'transport has been attracting more and more attentions around the world.Carbon emission of energy consumption by the construction and transport in 2010reached 2.15billion tons of CO_2,accounting for 29.7%of the total carbon emission in China.Energy consumption and carbon emission in the Yangtze River Delta in 2010contributed 17.5% of total amount in China.Hence,it's of great significance to investigate carbon emission of urban residents'transport in the Yangtze River Delta,which is helpful to find the path to low-carbon city development.It will also play an important role in achieving the China's national carbon reduction target by cutting per unit of gross domestic product(GDP)by 40%-45% by 2020against the 2005's level.This paper chose three representative cities,including Nanjing,Ningbo and Changzhou as the case studies,based on the criteria of city level,population size,demographic characteristics,economic development and urban spatial structure.This paper analyzed the characteristics and the impact mechanism of carbon emission for urban residents'transport in the Yangtze River Delta at the individual level,by collecting the first-hand information on carbon emission of urban residents' transport with a structured survey questionnaire and a systematic sampling method.The results showed that per capita carbon emission of urban residents'transport in 2010in the Yangtze River Delta was about 1 121.9kg CO_2.The proportion of carbon emissions between daily commuting and long-distance travel was 75∶25.The dominant factors to influence carbon emission of urban residents'daily commuting were transport mode,commuting distance,household income,age and gender,whilst those for long-distance travel were travel distance,transport mode and household income.Three counter measures should be seriously considered in policy-making:(1)Differentiated governmental intervention and economic levers should be applied to effectively control the growth rate of household car ownership,and the consumption on small-displacement and clean energy automobile should be encouraged,to achieve the equilibrium of automobile industry development,rigid demand of household car ownership and energy saving demand.(2)Optimize urban function pattern and develop public transport network.(3)Strengthen the publicity and education on energy conservation and low-carbon awareness to encourage and guide the public transport travel.