The concept and practice 'of the protection of historic complexes (old-town districts) in the USA varies greatly from the methods adopted din European countries. It consists in a demarcation of the so-called historic districts which, as a rule, are covered by special legal regulations. Due to a considerable legislative independence of administrative units (including towns) there may exist certain differences. However, even with this in mind, it is still possible to think of the emergence of a new branch of law, namely Historic District Law based on ample practice of American states and towns in the sphere of the creation of regulations on the demarcation and protection of historic zones. The main principles of the said Law may be rendered as f ollows : — The historic zone covers a precisely delineated area in the town’s zonning map. — Special Boards of Architectural Review are established which supervise all changes in the buildings situated in a given zone. — The Boards undertake firm decisions in this field (permissions to build) executed under supervision of municipal administration or specially appointed officers of the historic zone. — The above decisions are subject to appeal in the court or in a quasi-juridical body brought to life to this end. — The infringement of the law on historic zones is punished with a fine or imprisonment. Restoration works in these zones are carried out by owners of the renewed buildings. They may receive financial assistance from the authorities but only in exceptional cases. Various social organisations and foundations also participate actively in these works.