Split traces its roots from ancient Salona which was abandoned during the invasion of Slavs and Avars, and also destroyes after that. A big number of inhabitans had moved to Diocletian's palace, from which the city of Split has developed. During the Middle Ages, class differences among the citizens of Split were increasing and the power was beginning to concretate in the hands of the nobility. In parallel, the town itself was going trough a transformation into a medieval commune and upon the arrival of the Italian on the post of mayor, the common law was being codigied into a statute. Criminal justice system, as the main parto of this thesis, was described on the basis of the Statute of Split from 1312. and its later reformations. As part of the presentation of penal provisions, the provisions which protect both individuals and the community are presented. Furthermore, since the foreigners were also participant sin everyday life of medieval communes, a separate chapter defines their status in the criminal justice system. Also, the position of women is presented as well and the provisions which were mostley related to them refer to rape and witchcraft. The criminal justice system also consists of the criminal proceeding itself. The proceeding could have been initiated by an individual or ex officio. Plaintiffs, defendants, witnesses, judges and attorneys took parti n litigation itself. Their rights and obligations were regulated by the statute and it prescribed manners of proving, as well as punishments for each offence.