This article presents a first approach to the issue of current changes in the economic and political system in Cuba. The research covers various aspects of these transformations, relying on the reflection of main changes in official documents, considering it as the stage of institutionalization of the measures previously conceived as temporarily. The paper offers an analysis of some decisions made by the Communist Party of Cuba in the latest Congresses, as well as a comparative study of the constitutions (1976, 2019 and the project of the letter) of the country to show the distancing of the current Cuban socialist system from the socialist foundation that existed before the collapse of the USSR, nourished by Marxist theory. The article states that the main (structural) shifts have taken place since the VI Congress with the application of the updating of the Cuban economic and social model. Furthermore, it proposes a study of these transformations in the concept of socialism through the perspective of Ernesto Che Guevara’s thought.