The speech-act theory, developed by J. Austin and J. Searle, regards the utterance of a sentence under certain conditions (speech act) as a minimal unit of linguistic communication. One of the main objectives of the theory is to clarify the constitutive rules that define the propositional-illocutionary acts performed in a given utterance act. Many literary studies (e.g, S. Levin, R. Ohmann) have applied this theoretical framework for the definition of literature, where the fictionality is the central problem. The fictional discourse is defined by Searle as follows. The author actually performs a series of utterance acts with the intention of invoking the extralinguistic conventions (genre-rule) that suspend the contextual conditions normally required by the constitutive rules of the propositional-illocutionary acts. Though this definition is clear, I think it is not satisfactory for the literary discourse. The fictionality of imaginative literature is to be defined by the reader's peculiar attitude, which, contrary to the normal one, enables the reader to consistently infer the possible speaker and the possible world so as to make the quasi-speech acts felicitous.