Like many other sub-fields of sociolinguistics, two seemingly unbridgeable gaps exist in the sociolinguistic study of multilingualism and identity in urban settings. First, existing studies tend to examine Western and/or English-speaking societies only; and moreover, they do so by using either quantitative or qualitative methods and rarely considering both approaches. As a result, relevant theories have been developed without taking into consideration cases outside these sites using a more comprehensive methodological approach. This chapter presents a case study of urban multilingualism in Ningbo in Eastern China to demonstrate how investigations of non-Western/non-English multilingual settings incorporating interdisciplinary methodologies can help to validate, challenge and, more importantly, expand our understanding of the sociolinguistics of multilingual identity, both theoretically and methodologically. Informed by a variationist approach and mixed-methods designs, the case study not only presents the multilingual sociolinguistic reality of Ningbo, but also shows how an interdisciplinary perspective enriches the field of sociolinguistics.

China is one of the most multilingual countries in the world. The government of the People’s Republic of China promotes the country as a harmonious and unified nation with 56 distinct ethnic groups who speak more than 400 heritage languages. The government has not only legally recognized multilingualism but also publicly encouraged a climate where the teaching and learning of a variety of heritage languages can flourish. This chapter provides insights into our understanding of Chinese language policy and implementation and heritage language maintenance and is based on empirical research and case studies in China’s multilingual regions and provinces. It examines the application of the Chinese government’s language policy and heritage language practices over the last 30 years with its underlying language ideology and practices, revealing de facto language policies. While modern standard Chinese (Putonghua) continues to be a powerful factor in both consolidating and probing educational, cultural, social, and political discourse as well as the spatial environment, Xi Jinping’s recent “One Belt and One Road” project has created a new linguistic environment, which has affected the use of heritage languages within diverse minority groups. This has accelerated the deep concern shared among those advocating heritage language maintenance in China.