ENDuring the 1837-1850 Simonas Daukantas employeded as a assistant of metricist of the Lithuanian Metrica in St.-Petersburg (Russia). It is necessary to consider his research of the Lithuanian Metrica, copying of a documents and creation of their collections as the first and bright stage of study of the Lithuanian Metrica. S. Daukantas conducted the researches independently, without support of a patrons, constantly crossing through rules of imperial bureaucracy. Daukantas worked and wrote for the Lithuanians. He saw in the Lithuanian community a significant number of the developed people. Therefore it was necessary to begin complicated and ungrateful task of the publisher of historical sources.