In most languages, focus (i.e. highlighting information) is marked by modifying the melody of the sentence. But how is focus marked in a Chinese dialect with eight different citation tones and a complex tonal phonology? This thesis investigates the connection between tonal realization and tone change (tone sandhi) in Wenzhou Chinese, and whether and how such a connection is conditioned by prosodic structure and focus marking. Experiments were conducted with young speakers of Wenzhou Chinese, whose speech was acoustically analyzed so as to investigate the application domain of tone sandhi and the influence of focus thereon, the tonal realization on the word and phrase level and its interaction with focus, the pre-planning of sentential pitch, as well as the realization of referents with different information statuses. The experimental findings suggest that the application, but not the implementation, of tone sandhi is independent of focus, and that focus and prosodic structure have similar but independent effects on the realization of lexical tones. It is also shown that pitch scaling is sensitive to syntactic structure and complexity, and that the marking of givenness, broad focus, and narrow focus leads to discrete levels along the same acoustic parameters. These findings are of interest to researchers working on lexical tone, prosodic structure, and how information structure categories such as focus affect tonal realization and prosodic phrasing.