The process of Slovenia entering into the European Union, was inevitabely connected with adaptation of Slovenian legislation according to provisions, wich are valid for all member States of European Union, and that is why the harmonisation and unification proceses, which can only take place through well planed comparative studies, which were executed in the frame of research program, were necesary. Contribution of research program to the proces of adaptation of Slovenian legislation is the amending of Company Act with ZGD-F novel, the regulation on entering the companies into the courts register, only partial contribution to change of Takeovers Act and partial contribution to the new Obligation Act and to provisions on Public orders.