Matrimonial property is an institution of family law. According to the legal provision in the Family Law, "Marital property is property that the spouses acquired through work during the duration of the marriage union or originates from this property." The institution of marital property is important because by entering into marriage, the spouses establish, in addition to the life partnership, a joint household in which the economic function of marriage is fulfilled. The paper begins by citing and describing the Laws that influenced the development of the institution of matrimonial assets. The first law by which Croatia independently regulated the property relations of spouses was the Law on Marriage and Family Relations. The property of the spouses was joint and separate. Before the Law on Marriage and Family Relations, the property relations of spouses were governed by the Basic Law on Marriage. Both laws were effective during Yugoslavia. The second part of the paper, i.e. the main part of the paper, is focused on the institution of matrimonial assets in the positive legal legislation of the Republic of Croatia. After independence, Croatia passed the Family Law in 1999 and replaced joint ownership with marital assets, i.e. joint ownership. Marital property is analyzed, which can all be part of marital property, how spouses can manage marital property, and how marital property can be divided and how it is divided in the event of divorce, separation or death of a spouse. In addition to matrimonial assets, the paper deals with the concept of spouses' own property, the marriage contract and the property effects of cohabitation and registered partnership. Which were mentioned only briefly. In conclusion, the paper ends with a presentation of the differences and changes that occurred during the transition from joint ownership to marital property, co-ownership.