Adopting the perspective of identity work and the membership categorization device, the present study, examines the transcript of tape-recorded medical business conversation to reveal how a medical consultant uses deictic strategies to construct an expert identity for communicative purposes. It is found that: (1) the consultant employs personal pronouns and self- and other-referring forms to construct the expert identity. (2) the personal pronouns include the normative and attributive first-person pronoun, both singular and plural; the discourse function of the plural can be categorized into “institutional”, “expert-based”, “quotational”, “interactional”, and “patient-based” while that of the singular, “expert-based”, “structural”, “quotational” and “patient-based”. (3) self- and other-referring forms are realized by altercasting self- and other-referring identity markers. The study proposes an interpretation under identity work model, claiming that person-pronouns, social address form, together with membership categorization device can be employed as a rhetorical strategy to perform identity work, termed as identity rhetoric.