The article is focuses on the importance that the principle of the oral trial has as basis for the Paraguayan Civil Process Reform, considerating that Paraguay is at the beginning of the study of a proyect of General Proceeding Code, based on the Model Code. This indicates haw necessary it is to change some paradigms in all those people involved in the reform justifying the advantages of the oral system to build up a better method for judging. On the one hand, this vision connects the principles of the oral trial with other principles also important to it; on the other hand, it evaluates not only its advantages but also its objection, synthesizing, the inmutability of the civil process, from its origins up to this days (especially in Latin America); finally it express our opinion as final thesis, argueing that oral trial is the worldwide tendency accepted by the modern process as better option to get a more efficient justice.