This paper aims to investigate semantic and syntactic characteristics of the reflexive form tua-eng‘self’ in Thai and analyze reflexive constructions within the framework of Cognitive Grammar, adopting van Hoek (1995, 1997)’s approach. To observe how the reflexive appears in actual usage, 500 instances of tua-eng were collected from the Thai National Corpus (tnc). The reflexive is examined in relation to its antecedent regarding animacy, structural proximity and grammatical positions. Moreover, frequently encountered reflexive constructions are identified. The study claims that the prototypical reflexive construction in Thai is one in which the antecedent serves as a subject and tua-eng as a direct object. Other constructions are extensions from the prototype and can be accounted for when the antecedent’s point of view and the viewing relation are taken into consideration. The reflexive constructions in Thai are hence a network of related schemas that are prototypically organized.