This paper provides experimental and theoretical evidence for the syntactic realization of an implicit possessor argument in Relational Nouns (RNs, e.g. "father") in Mandarin Chinese. The results of Experiment 1 show that the antecedent of the implicit argument in RNs must be a noun phrase (NP) in the sentence where the RN is located, rather than an NP in the discourse context. Experiment 2 shows that the implicit argument of RNs must be bound by a c-commanding NP. The results exclude the possibility that the RNs' implicit argument is a pronominal that would link to a contextually salient NP and would not require a c-commanding referential antecedent. Rather, the experimental results show that the identification of the antecedent of the RNs' implicit argument is constrained by the same principle of binding theory that constrains the reflexive zìji 'self', specifically requiring a c-commanding antecedent.