Anglická anotace This thesis deals with the marriage law. Its aim is to study an approach to the institute of marriage from the point of view of the canon law in Roman Catholic Church in contrast to the family law in the Czeh Republic in focus on the conditions which are important for entering into marriage. In the first instance the thesis concerns with the specification of marriage in both branches of law, then the aims and effects of marriage, the form of entering into marriage, the suitable subjects for marriage including the subjects that have the right to marry somebody and also the issue of validity of marriage. Key word: marriage, validity, canon law, marriage law, condition