The dissertation describes development of the preparation of children for reception of the first Communion and the first confession. In particular time periods of our history the church passed its teaching and faith on in a lot of various ways. The first Christians educated the newcomers in catechism. In the Middle Ages begins the development of catechesis and primarily of preaching, which should educate both children and adults. There isn{\crq}t still much time devoted to children and their preparations for reception of the sacraments; children cannot receive the sacrament until they reach an older age. Change in a bestowal of the sacraments is brought by a decree Quam singulari promulgated in 1910 by Pius X. It{\crq}s a decree on the age at which children are to be admitted to first Communion and it still influences the pursuance of preparing the new communicants for the reception of the sacraments. In my work I described, with the help of an available literature, the course of the preparations of the new communicants from the promulgation of the decree until now. I am also stating the methodic materials used by those, who lead those preparations.