ABSTRACT: Praetorian law and civil law are two closely related branches of Roman private law. Civil law is a set of legal norms, specific to the old era, when law was confused with religion and morality, legal relationships were simple and rare, and legal norms could not be modified or abrogated due to the conservatism of the Romans, who considered that they came from to the gods. Civil law was exclusivist, because it applied only to Roman citizens, and formalist, because civil law acts were concluded by performing some rituals and pronouncing some solemn words, the mistake of which led to the non-existence of the act. Because of this, ius civile delayed the evolution of Roman law. As the Romans gained legal experience, their practical spirit prompted them to resort to praetorian law. It appeared as a reaction to the conservatism of civil law norms and is a set of legal procedures, which contributed to the updating of civil law norms and the evolution of private law procedurally. KEYWORDS: Civil Law, Praetorian Law, Roman Private Law