The author examines the theoretical aspects of import substitution, follows the evolution of the concept of «import substitution» depending on the tools used for its study. The concept of «import-substitution» is clarified from the point of view of its component parts and identification of particularities. The author notes that there are a lot of completely opposite interpretations of this concept with fragmentary characteristics and various approaches to the analysis of the import substitution process. With the help of the categorical methodological approach, the author identifies the components of import substitution with the definition of their characteristics. As the result, most capacious and accurate definition is obtained.