This master’s thesis works out the topic of catholic reformation of the dalmatian population in the 18th century with a special focus on the areas of the archdiocese of Zadar and the diocese of Nin. This research is intended as a contribution and an incentive to the research of the cultural and church history of Dalmatia of the 18th century. The narrower theme of the research is the institution of marriage as an example of the study of catholic reformation as a cultural process. Accordingly, in order to examine the religion of the people, the research publishes a number of unpublished archival works such as canonical visitations of some parishes of the diocese of Nin and the archdiocese of Zadar, as well as marriage records and lawsuits of these dioceses. After the introductory chapters in which, among other things, the methodology and the meaning of some key processes and terms are described, the paper provides an overview of the Catholic institution of marriage. This overview includes the foundations of Christian thought on marriage, that is, the Bible and the teachings of the church fathers. As the theme of the work is Catholic reformation, the climax and the sum of Catholic teaching on marriage is taken from the decrees of the Council of Trent (1545 - 1563), the Roman Cathecism (1566.) and the Corpus iuris canonici (1582). After the presentation of Christian, Catholic law and the doctrine of marriage, the paper presents statutory and common marriage law according to similar categories by which the Catholic doctrine of marriage is described, and to the extent to which it correlates to the Catholic reformation. The fourth and fifth chapters are a representation of the interaction of these two schools of thought, that is, of the two cultural entities, common and Catholic. The principle of description is from the general to the specific. Therefore, the description of the context in which the Catholic officials were implementing the Catholic reformation precedes the description of the actual implementation along with the church officials’ (in)ability and (in)competence in implementing the Reformation. This is finally presented on the marriage cases themselves, i.e. cases of misdemeanors and violations of marriage.