Abstract: Mei-Cl-NP ₁+V+ Mei-Cl-NP ₂+ De+NP ₃sentences involve the unique Mandarin phenomenon of " Mei" -phrase as a bound variable,which has not been discussed in depth in previous studies.From the perspective of generative grammar and formal semantics,the paper holds that Mei-Cl-NP ₂is bound by the universal quantifier phrase Mei-Cl-NP ₁,and its function is to help NP ₃become a variable so that NP ₁and NP ₃can form a matching relationship.Syntactically,this use observes the constraints imposed by Binding Theory. Mei-Cl-NP ₂cannot be a co-argument with its antecedent,and has to be a modifier of the co-argument.Semantically,NP ₃cannot be definite,and the cardinality of the set it denotes must be greater than one.According to whether NP ₃is unique for NP ₂in real life,the construction has two types of semantics:a one-to-one relation and a non-many-to-one relation between NP ₂and NP ₃. Mei-Cl-NP ₂is ambiguous,though the bound variable reading is salient in some cases,which is usually related to individuality or non-repeatability of the event in question.The paper also points out that yi-Cl-NP, ge,and shui with the help of dou can all have the same pattern as mei-Cl-NP ₂,though they have different matching requirements.