Within the context of endangerment of family's treatment during the process of legislation, on the example of Mexico's legislation, the Authors present the conception of marriage and family as an institution from anthropological and theological perspectives. According to the religious tradition of the Catholic Church, family and its source - marriage, are natural institutions. This aspect has its basis in anthropology (1); and, likewise, characteristics of marriage according to the natural law, in i.a. provisions of canon law (2) and its aims - civil and religious (3). Marriage and family are institutions (4), based on anthropological “principium”, to which referred Christ in His preaching (5) - person in the unity of body and spirit of two people, connected with love (6). It is necessary to use the principles of natural law to interpret the institutions of marriage and family adequately, also in a process of law-making and applying provisions of law.