<p>Current understanding of dialect-based discrimination and linguistic microaggressions in China remains limited, particularly in terms of how these dynamics operate across different regional and social contexts. While existing studies often focus on overt language discrimination, the covert mechanisms of microaggressions remain underexplored, especially in non-Western settings. This qualitative study examines dialect-based discrimination and linguistic microaggressions in China, focusing on experiences of marginalization and identity negotiation among speakers from both Mandarin-dominant and dialect-dominant regions. Semi-structured interviews were conducted with 15 participants aged 20 to 39 from diverse linguistic and regional backgrounds. Six themes were identified: (1) inner circle vs. outer circle language dynamics; (2) code-switching as a tool for navigating social boundaries; (3) bidirectional nature of language marginalization; (4) linguistic insecurity and social integration; (5) diminishing linguistic boundaries, and (6) coping strategies and adaptation. The study reveals how dialect use intersects with social boundaries, creating contextual exclusion for both dialect and Mandarin speakers. Participants also described their coping strategies, which included code-switching and disengagement. By situating dialect-based microaggressions within the broader framework of social boundaries, this research extends understanding of linguistic discrimination and its implications for identity in multilingual societies like China.</p>