Editor’s Note: All over the world, once the process of urbanization began, cities were no longer demographically native and socially homogeneous. While they received and accommodated more and more people flowing in from different regions or countries, firstly from nearby rural areas and then from far-reaching provinces, their social structure became more and more diverse. Globalization further strengthened this trend by promoting the demographic mobility globally. More than often, the agglomeration of people did not lead to convergence but conflicts, due to the remarkable disparities among people coming from different parts of the world, in terms of culture, religion, customs, income, and so on, in particular the view of values. Social segregations between the rich and the poor, the young and the old, natives and foreigners, and local residents and immigrants became a quite popular phenomenon in cities, which was expressed in both a physical and a non-physical way. The juxtaposition of formal and informal housing, the segregation between social and commodity housing, the clearance of informal sectors, the discrimination on immigrant families, and the eviction of floating population are some presentations of these conflicts, all of which became a huge challenge to urban governance. Under that circumstance, social inclusion has become a hot topic in both the academic and political arenas and community building and community governance have got more and more importance as potential countermeasures. However, people in different countries usually have different interpretations on community connotation, different ways of community building, and different institutions of community governance, which is due to the differences in the aspects of history, culture, politics, administration, and so on, as justified by the four papers included in the Theme Documents of this issue. They are the periodic outcomes of the research project of Transition Towards Urban Sustainability Through Socially Integrative Cities in the EU and in China which is funded by the EU’s Horizon 2020 Research and Innovation Programme within the framework of the Joint Declaration on Urbanization Partnership between China and Europe issued in 2012 and involves 14 research institutes from both China and Europe. Based on comparative case studies between Chinese and European cities, they demonstrate the significant role of communities for the building of socially integrative cities in both China and Europe, regardless of the different interpretations on the concept, as well as the possibilities of combining community building with cultural heritage preservation, education promotion, and place making.