Before the Republic of Croatia became member of the European Union, particular short comings in administrative justice had been indicated. The main aim of this document is to investigate the problems of administrative justice reforms on the territory of Republic of Croatia that had been introduced by the law about the administrative disputes that had been passed in 2010 and put into effect on January 1, 2012. That law is significantly changed and complemented in relation to the law about the administrative courts from 1977 and law about administrative disputes from 1991. Finishing work is systematizing Croatian law history since the disband of the austro-hungarian monarchy until the establishment of independent Republic of Croatia and it induces the institutions and laws from that period. Basic characteristics of the administrative justice, for example: administrative dispute, principles of administrative dispute and models and organization of administrative justice, are also being considered. To sum up, the number of solved and unsolved administrative subjects that are related to administrative disputes is being analyzed through all 4 administrative courts and High administrative court of Republic of Croatia. Based on results, the argumentation review is given.