The article deals with determining the place of the Law of Ukraine «On Administrative Procedure» (LAP) in the system of Ukrainian legislation and its impact on the systematization of administrative procedure legislation in general. The author analyzes the general features of such a type and form of systematization as codification and compares it with the adoption of the LAP and its impact on current and future legislation. On the one hand, the author emphasizes such common features and positive impact of the LAP as improvement of the structure of legal acts, improvement of their logic and terminology. After all, the LAP introduces uniform principles of administrative procedure, general rules for consideration and resolution of cases based on applications of individuals and on the initiative of an administrative body, requirements for the execution of administrative acts, administrative appeal, enforcement of administrative acts, and early termination of administrative acts. On the other hand, the LAP mainly fills in the gaps using the best practices, doctrine and experience of countries of Western legal and political culture, especially Europe. In the short term, the LAP may not change the number of legislative acts, and is likely to have a rather limited impact on reducing the volume of procedural parts in special legislative acts. At the first stage, the amount of procedural regulation may even increase. This is due to the fact that in order to eliminate conflicts and gaps, it may be necessary to introduce additional «linking» provisions with the LAP, and sometimes even temporary duplicate provisions, etc. In the medium and long term, we can predict that the LAP will play the role of the main procedural regulator in public administration. The LAP should act as a general law for all sectors of public administration. And here, indeed, the LAP should serve as a measure for reviewing, streamlining and reducing special regulation. In the future, special legislative acts and other regulations will continue to be in effect, and, if necessary, preserve or establish specifics of regulation. However, it will be possible to reduce the scope of special procedural regulation more and more radically and systematically. The LAP will be especially valuable in the future, as special legislation will have less and less need to regulate the procedure. In this case, the regulatory value of the LAP itself will be maximized, as it will be easier for both public administration and private individuals to interact on the basis of common principles and rules. The LAP is extremely valuable for its principles, which are not only the basis for this law, but also a measure for resolving conflicts and filling gaps in all administrative procedure legislation. Particularly important are such principles as guaranteeing the right of a person to participate in administrative proceedings, formality, and reasonableness. Key words: general administrative procedure, systematization, codification, principles of administrative procedure.