The reform movement of a part of the lower Catholic clergy in Croatia had several phases. The activity of precursors of the reform movement (until 1919.) showed that a part of hierarchically lover clergy was not satisfied with the existing relations within the Catholic Church. At the same time it was an indication that soon a movement would be formed with the aim to carry out the reforms which were supposed to democratize the Catholic Church organization and improve the material and social position of its lower clergy. The reform movement got its full swing in the newly founded Kingdom of Serbs, Croats and Slovenes. "The contemporary wishes", i. e. the demands of the Catholic priests in Croatia, formulated in so-called "Bolshevik synod", presented the orientation in the struggle for carrying out the reforms in the Catholic Church. It is significant that none of demands touched the basic religious questions, i.e. dogmas, but were limited to the questions of the church discipline and organization. The Catholic Church authorities in Croatia condemned sharply the reform movement and its demands. The turn of 1919 to 1920 witnessed the differentiation among the priests regarding the question of further conducting of the action for the reform of the Catholic Church. Most of them resolutely stuck to their opinion that the required reforms had to be carried out in the legal way within the Catholic Church itself. But some thought that the success was possible only if all the connections with the Catholic Church were stopped and new independent religious community formed. The Koprivnica phase of the movement (1920) showed that Yugoslav Catholic episcopate, complying entirely with the attitude of the Holy Chair regarding the Czech reform movement, had no intention to accept the demands, now somewhat changed, of the subordinate clergy and that occupation of the Roman Catholic parish by force and its transformation into the "Croatian-catholic parish" was not realizable. Regardless of the strict church punishments, the movement was kept, mor or less, within the range of the Catholic Church until first excommunication in 1921. In the last phase (the period between 1921 and 1923/24) the reform movement entered its seemingly hopeless crisis and stopped definitely its organizational and dogmatic relations with the Catholic Church. Political parties and groups in Croatia looked at the reform movement of the priests solely from the aspect of their narrow political interests. In order to stop the reform movement the Catholic Church authorities had the support, based on the law, by the highest state bodies. The only way to overcome the crisis of the movement and realize the longed for reform was to pass to the Old Catholic religion. The impossibility of carrying out the reform within the Catholic Church in Croatia made a part of dissatisfied lower clergy found new religious community - the Croatian Old Catholic Church. In first five years of her existing Croatian Old Catholic Church made his own institutions and go through an experience of firs crisis. With year of 1929 finish the time of her consolidation.