Abstract: In the process of rapid urbanization， the unprecedented population movement brings about regional cultural collision, driving economic growth while profoundly affecting social harmony. Based on the public data of the China Judgments Online, the Dictionary of Chinese Dialects， and the 2017 China Migrants Dynamics Survey， this paper takes Guangzhou， Shenzhen， and Dongguan， three cities with a net inflow of over 10 million people， as examples for empirical analysis. By choosing dialect distance as a proxy variable of cultural differences， we investigate how it affects the hometown gang criminal behavior of the urban migrant population. The empirical results show that there is a significant positive correlation between dialect distance and hometown gang crime among the migrant population. For each additional unit of dialect distance， the likelihood of migrants choosing hometown fellows as accomplices in crime increases by 8.3%. Mechanism analysis shows that the peer effect formed by dialect distance is a main factor for the increase of gang crime among migrants. Under the same conditions， the greater the migration distance， the greater the cultural gap between the migrants and the local population. Specific to social networks， it is reflected that migrants tend to trust members of the hometown group rather than the locals， which leads relatively closed clusters of community， enforcing the peer effect and increasing the possibility of participating in gang crimes. From the perspective of dialect distance， this study quantifies the impact of cultural conflicts on the harmony and stability of urban society in the process of urbanization， enriches the theoretical exploration of culture influences on migrant crime and its governance， and has certain implications for promoting a new type of people-oriented urbanization.

Key words: migrants, dialect distance, cultural differences, peer effect, fellow organized crime