The purpose of this work is shown expert witness as an exemplary tool for determining the factual situation in the administrative procedure and in the administrative dispute. Except this theory it is applied practical example of practice which will be the finding and opinion of an expert witness in the administrative procedure and the verdict of the administrative court in the administrative dispute at which the expert witness was admitted. An administrative procedure is governed by the Law on General Administrative Procedure (NN 47/09) and the administrative dispute on Administrative Disputes Act (NN 20/10, 143/12, 152/14 29/17). Article 33, paragraph 5 of the same law stipulates that the court performs the expert analysis in accordance with the rules governing pleadings under civil procedure pursuant to the Civil Procedure Act (NN 148/11, consolidated text, 25/13, 89/14). This paper work is explained the appointment of expert witnesses, who may be expert witnesses, expert assignment, expert assessment of legal and natural persons, duty of expert witness, expert's exemption, appointment of experting witness, expert management, expert's finding and expert's opinion