The core value of the expo theme can be interpreted as following: The City, built by people, has been evolving and growing into an organic system. People are the most dynamic cells with the best ability to innovatein this system. People’s life is closely interactive with the urban morphology and development.
　　With the raped urbanization, a more extensive relationship and interaction has been established　between the city organic system and earth’s　biosphere and resource system. People, city and earth　are just like three organic systems linking with each other and fusing into the integrity throughout the whole process of urban development.
　　For further reflect of the theme "Better City, Better Life", five sub-themes are defined;they are "Blending of Diverse Cultures in the　City","Economic Prosperity of the City","Innovation of Science and Technology in the City", "Remodeling of Urban Communities", and　"Rural-urban Interaction".

　　世博会主题核心思想可以这样理解：城市是人创造的，它不断地演进、演化和成长为一个有机系统。人是这个有机系统中最具活力和最富有创新能力的细胞。人的生活与城市的形态和发展密切互动。

随着城市化进程的加速，城市的有机系统与地球大生物圈和资源体系之间相互作用也日益加深和扩大。人、城市和地球三个有机系统环环相扣，这种关系贯穿了城市发展的历程，三者也将日益融合成为一个不可分割的整体。

　　为了更好地理解“城市，让生活更美好”，上海世博会还设有五个副主题分别是“城市多元文化的融合”、“城市经济的繁荣”、“城市科技的创新”、“城市社区的重塑”、“城市和乡村的互动”。