否定标记是语言差异的重要体现，对方言中的否定标记进行考察，一方面有利于增进对具体方言的认识，另一方面可以帮助我们认识方言与普通话之间的差异与联系。莆仙方言口语中的否定标记“无”与普通话否定词“不”和“没”存在语义对应，值得我们关注。本文首先描写了“无”的句法分布，对它进行了相应的语义解释，简要说明了“无”与普通话否定词“不”和“没”的对应关系；然后以形式语义学为指导，用逻辑表达式对“无”的否定语义进行刻画，明确了“无”的否定类型，得出结论，作为否定标记的“无”只能进行内部否定；最后分析“无”的辖域范围及否定焦点，利用重音、虚词和语境信息，对“无”的否定歧义进行了分化与消解。

Negative markers are an important manifestation of language differences. Investigating negative markers in dialects is not only beneficial for enhancing our understanding of specific dialects, but also helps us understand the differences and connections between dialects and Mandarin. The negative marker "无" in spoken Putian dialect corresponds semantically with the "bu" and "mei" in Mandarin, which is worth our attention. Fristly, we describes the syntactic distribution of "无" and provides corresponding semantic explanations, briefly explaining the corresponding relationship between "无" and the negative words "bu" and "wu" in Mandarin; Then, guided by formal semantics, we use logical expressions to characterize the negative semantics of "无", clarify the negative type of "nothing", and get to know that the negative marker "无" only carry out internal negation; Finally, we analyze the scope and focus of "无", by using stress, function words, and contextual information we differentiate and resolve the negative ambiguity of it.