Genre analysis, a new development in discourse analysis, has attracted much attention from linguists and applied linguists. The study reported in this dissertation falls into the domain of applied genre analysis based on a corpus of 30 job advertisements collected from two major professional recruiting websites on the Internet.A job advertisement (henceforth, JA), a promotional genre in nature, can be considered as a recognized genre text. The study aims to explore the structural pattern of this genre from a macroscopical perspective, and to examine the interpersonal meaning realized on the lexico-grammatical level from a microscopical perspective. Based mainly on the theoretical framework of move analysis proposed by Swales, and the Hasan’s notion of Generic Structural Potential, the structural pattern of job advertisements is examined with an aim of exploring how the discourse community of job advertisers fulfill their communicative purposes and why job advertisements are organized in the way they are. Microscopically, an analysis of the lexico-grammatical features of the genre in the tradition of Halliday’s functional grammar as its theoretical framework is also conducted. Variables such as the tenor, the mood system, and the dialogic nature of JAs are examined in detail to reveal the interpersonal relationships between the business company and the prospective employees. As the dissertation is chiefly devoted to the structural interpretation and lexico-grammatical explanation of job advertisements, an analytic approach is adopted. This approach is complemented by statistical methods in the detailed investigation of the data.Major findings of the study show that as a promotional genre, job advertisements serve other communicative purposes apart from the basic persuasive purpose. These communicative purposes include: to attract attention, to arouse interests, to establish credibility and promote good images, to inform readers, to inspire aspiration and stimulate actions, to serve as the first link, and to filtrate readers. The communicative purposes determine the structural pattern of this genre text to a large extent, which can be typically classified into nine specified moves. Three moves are obligatory, i.e. they are essential for the generation of this genre text. The other six optional moves are responsible for the variety of the texts and help writers meet different needs in different situations. The study also shows that the interpersonal relationships between the business company and the prospective employees can be maintained and enhanced through the mood system, the modality system and the dialogic nature of job advertisements. In practical terms, the insights gained from the study have potential value in improving writing competence of ESP learners. Theoretically, the present study may serve as a starting point to later, possibly more sophisticated, research of genre texts from various professions.