The object of this investigation are the Criminal subrogates, while these are part of the prision, this project is also about it. Moreover, in order to conceive the reason or origin of this text, it is necessary to refer to a legal and factual context and, to some reasons or arguments that lead to two main questions around which the research was conducted. The so-called context is developed in the first chapter written with three excerpts. The third deals with arguments, assumptions and reasons that, with the context, ended up in the aforementioned questions: How has the criminal surrogates’s legal development been?. This apart is developed in chapter two: criminal surrogates in criminal law. In the research, we realized that there isn’t clear and explicit definitions nor an exhaustive list of what the criminal surrogates are, so there is a need to identify the nature of the institution. There is also a rules and doctrinal's inconsistency. It was determined that the criminal surrogates are substantive legal institutes of criminal law, and for that reason they follow general purposes as retribution, prevention and rehabilitation. They are specifically a part of the Prison Law in which imprisonment is the visible. Specifically, they evaluate the need and usefulness of the execution of the prison sentence. The understanding of them in reforms are as institutions that serve to release or draw people from prison, without considering that: i) they are not release, and ii) Its objective is not limited to take out people from prison. Is the legal development of criminal surrogates need ?. In the project the convenience of an adequate legal development institute criminal surrogates was determined, therefore, the current inclination as mentioned, has been to make these reforms in order to counter the problems of overcrowding, wrongly taking as regulatory and factual equal levels of the institution.