ENThe aim of this research is to induct the evolution of harmonization of Europe Union legislation and the legal requirements of metrology for Lithuania Republic. The content of the article is divided into two parts. The first part of the article analyses the evolution of metrology in Lithuania, reveal the legal acts regulating metrological activities of the Republic of Lithuania, and induct international recognition of metrological surety ship of Lithuania. The second part analyses European Union's as well as national legislation regulating implementation of metrology in Lithuania and peculiarities of harmonization of national law with the European Union's legislation. Keywords: metrology; legal regulation; harmonization; European Union, market.