This dissertation investigates the linguistic phenomenon referred to as codeswitching in languages in contact´s literature. Code-switching consists of the alternate use of two or more codes by bilinguals or multilinguals in the same verbal interaction. The study of this discursive practice in several languages has obtained increasing interest in the last three decades. Two main approaches prevail: socio-pragmatic and grammatical-syntactic. Whilst the first approach focuses on the socio-discursive aspects of individual production through the categorization, quantification and analysis of codeswitching pragmatic functions and socio-psychological motivations; the second one intends to formulate formal constraints and patterns of occurrence of this linguistic behavior. The present work aims at presenting a bibliographic systematization and evaluation of the international literature in code- switching through the presentation and characterization of its major research lines, emphasizing the reference works and the directions provided by each approach. The need for the structured presentation of the several aspects of code-switching found in the literature in languages in contact is due to the fact that research on this phenomenon is incipient in Brazil and the access to this material is still restricted. This research, therefore, seeks to fill this gap and make the literature in code-switching accessible to the Brazilian academy.