The system of national law and the corresponding system of democratic authorities had to guarantee optimal protection of the individual’s fundamental freedoms and rights, and help to create human welfare. Science of administrative law is constantly evolving, and its insights are strategic in nature, oriented towards the future. There is often a struggle for new ideas, opinions, concepts, paradigms to be embedded or denied. The new, old, inaccurate statements are changed to be more accurate, the new ideas criticize the old ones, and life practices raise new problems that science must answer rationally. The science of administrative law in Lithuania is not static, it is constantly changing as the administrative law itself changes. The concept of administrative law is changing, its regulation is expanding. The science of administrative law is an integral part of Lithuanian law science, where the specialists of administrative law – scientists investigate the essence of this branch of law, its subject matter and separate institutes and in general all actual problems of administrative legal practice and science of the whoel country. This article is the first scientific research in the cycle of articles “Development of Administrative Law and Administrative Legal Doctrine in Lithuania”. The purpose of this article is to present the development of administrative law and administrative law doctrine in Lithuania since 1990 by analysing the works of Lithuanian scientists in this field through the categories defined in the research tasks. In order to achieve the aim of the article, the following tasks are raised: briefly to introduce and discuss the development of Lithuanian administrative law science and administrative law as a category, to define and analyse the goals of administrative law, the subject of regulation and the system of administrative law in Lithuania. In order to achieve the aim and tasks of the research, the analysis of the works of Lithuanian scientists and the main laws implementing the administrative legal regulation of Lithuania was performed. Methods. Historical comparative, documents’ analysis, synthesis and other methods were used for research. Results of research showed that Lithuania has modern administrative law and administrative justice system, that meets nowadays meets and European Union justice standards’ requirements. Conclusions. We can conclude that Lithuanian scientists understand the administrative law in broad sense as law of management and described quite wide range of its regulation subjects. After Lithuania’s accession to the European Union and its commitment to take over its acquis communautaire, the entire Lithuanian legal system, together with administrative law, had to adapt to change. Implementation of the provisions of the European Union legislation in Lithuanian law has become a priority. The abundance of administrative legal regulation at European Union level and the need for its application in the case-law have created challenging tasks for administrative law science. An accurate analysis of the implementation of European Union legislation in the systems of state power and public administration in Lithuania, analysis of administrative legal systems of the Member States of the European Union, search for similarities and differences, effective defence of the rights and legitimate interests of a person when a Member State misapplies (waives) the provisions of European Union legislation, the jurisdiction of national courts to deal with damages where, for example, damage caused by inappropriate application of European Union law is made by a court of final instance in the state, and other issues become the subject of modern administrative law research.