This thesis aims to contribute to the improvement of the paraphrasing competence, or the ability to produce synonymous sentences, of advanced learners of French as a second language (L2). While possessing solid grammatical skills, advanced learners still produce lexical and stylistic errors and experience difficulties in reformulating their discourse. Paraphrasing competence is crucial for a language learner since it helps him to present an idea more clearly or circumvent a lexical gap, while allowing the learner to express the same meaning in multiple ways. The theoretical framework adopted is Meaning-Text lin-guistic theory (MTT), that attaches a great deal of importance to the description of lexical and paraphrastic relations and uses well-developped formal tools for the modeling of these relations. The thesis has two objectives. The first consists in elaborating a methodology for evalua-ting the paraphrasing competence of a speaker. The notion of paraphrasing competence is defined, and a test assessing the ability to paraphrase is created and administered to An-glophone learners of French and native speakers. Quantitative and qualitative criteria to establish four levels of paraphrasing competence – elementary, intermediate, advanced and superior - are identified. Characteristics of advanced learners’ paraphrasing competence are described. While pro-ducing all types of paraphrases, the L2 learner uses less lexico-syntactic paraphrasing operations, such as synonymic, antonymic or derivative substitutions. His paraphrasing means are less diverse than those of a native speaker. He also produces a high number of paraphrases with lexical and syntactic errors. The second objective of the thesis is to propose a didactic method of teaching paraphrase, taking into consideration the challenges that paraphrasing poses for L2 learners, identified by means of the paraphrasing test. Concepts of the Meaning-Text Theory are presented in a user-friendly format so that the theoretical linguistic knowledge becomes more accessible to L2 learners. A structured and explicit teaching approach is adopted, based on: (i) a selection of key concepts pertaining to the paraphrase and their definitions ; (ii) a selection of MTT paraphrasing rules and their explanation; (iii) paraphrasing exercices.The advocated pedagogical approach may serve as a reference tool for paraphrase didactics in French.