Adopting methods of the questionnaire, matched-guise test and semi-structured interview among different occupational groups of migrants in Chongqing, China, the present study investigates the correlation between dialect competence, dialect attitude and social inclusion. The results show that entrepreneur migrants have the highest dialect competence, followed by labor migrants and intellectual migrants. All the migrants' attitude toward Mandarin Chinese, mainly reflected in the "emotional cognitive" and "social evaluation" dimensions, is significantly more positive than that toward Chongqing dialect. In terms of social inclusion, the entrepreneur migrants rank highest, followed by intellectual migrants and labor migrants. Statistics indicate that there is a significant correlation between migrants' social inclusion and their dialect competence and attitude (in particular, the "emotional cognitive" dimension of their dialect attitude plays an important role in affecting their social inclusion). In addition, the semi-structured interview reveals that the migrants' language environment of working and living is a crucial factor affecting their dialect competence, dialect attitude, and hence their social inclusion. Based on the results, this paper provides suggestions on how to improve migrants' social inclusion from a language planning perspective.