The article provides an overview of the documents from the Russian State Archive of Economy (RGAE), which reflect the dynamics of financial support for all aspects of life in the Latvian SSR from August 1940 to May 1945. These documents are stored in series 25-30 of fond 7733 “Ministry of Finance of the USSR. 1917-1991” and have not yet been studied by researchers. Series 25 and 26 contain rich data on financing of various branches of the Latvian economy, including those not developed in Latvia previously. The peculiarity of currency circulation in late 1940 -early 1941 is described. There were two currencies in circulation in the Republic at the time: the lats and the rubles. The documents show that the central government policy did not seek to destroy private farms. On the contrary, the authorities provided Latvian peasants with loans on favorable terms to help the population to adapt to Soviet life. The documents inform that 50 machine-tractor stations were built in Soviet Latvia over a short period of time. These stations were exempt from taxes. Series 26 contains documents that provide data on plans for financing the social sphere in Latvia in 1941 to the extent of 50.8% of all expenses. This figure was significantly higher than in any other union republic. In the RGAE there are unique documents on the financing of Soviet Latvia during the Great Patriotic War. There are cost estimates that allow to study state expenditures on the functioning of the Soviet Latvian government in the period from 1942 to 1943. In series 29 and 30, there is much information on the transfer of funds for the restoration of the destroyed economy and social sphere of the Latvian SSR and on the priorities of financial security. In addition to the restoration of enterprises, institutions, and housing, significant funds were transferred to the implementation of new social projects: construction of higher educational institutions, technical schools, schools, libraries, museums, theaters, and cinemas.