Discourse marker analysis has been widely studied, leading Fraser (1998: 301) to call this subject `a growth market in linguistics'. In our present research, we extended the study of discourse markers to the Chinese marker meiyou, which has traditionally been treated as a negator (e.g. Biq, 1989; Teng, 1973a, 1973b, 1975). The corpus studied here contains 40 conversations, totaling 482'27”. The analytical framework adopted in the study was drawn from van Dijk's model (1979), which mainly consists of a semantic/textual level (i.e. sequences of utterances/propositions) and a pragmatic/interactional level (i.e. speech-acts). A total of 141 occurrences of meiyou were identified as discourse markers in the corpus: 13 of them occur at the textual level and 128 of them at the interactional level. Thus, meiyou occurs more frequently at the interactional level than at the textual level. At the textual level, meiyou introduces an answer to a self-inquiry or self-correction. At the interactional level, meiyou mainly serves as a response to provide information, as a marker of correction/clarification or evasion, and as a response to praise or gratitude. In particular, with respect to meiyou's interactive functions, we use the concepts of preference structure (Sacks et al., 1974) and face-threatening acts (Brown and Levinson, [1978] 1987) to analyze the collected data. We further demonstrate that intersubjectification (Traugott and Dasher, 2002), a mechanism whereby meanings become more centered on the addressee, is involved in the development of the discourse marker meiyou.