[Context and Motivation] KAOS is a goal-based modelling language used to model requirements and has been used in industrial and academic pro-jects. Often, the language has been extended to incorporate new constructs related to an application domain. It will continue to be extended. [Ques-tion/Problem] Identifying and choosing existing KAOS extensions based on their constructs and characteristics can be a challenging task due to a great number of the existing KAOS extensions. Thus, a Systematic Litera-ture Review was conducted to identify and analyse KAOS extensions. This paper contributes by identifying and analysing the existing KAOS exten-sions and their constructs. [Principal Idea/Results] The results point to 50 papers (each one presenting a different KAOS extension) and 221 con-structs proposed. The extensions and their constructs were analysed accord-ing to well-defined questions in two dimensions: a general analysis and a model-based analysis (to characterise the extensions from semantic and syntactic definitions). The application domains targeted by the KAOS ex-tensions, concepts definition, syntax (abstract or concrete) and details about the abstract and concrete syntaxes’ definitions are presented as re-sults of our analysis. [Contribution] Thus, the analysis of the KAOS ex-tensions and their constructs can be easier the identification and choice of existing KAOS extensions based on their characteristics and constructs. Additionally, a catalogue of KAOS extensions and their constructs was proposed to support the extenders searching for KAOS extensions and con-structs identified by this SLR