The article and the published documents study the previously unknown documents on the judicial reform. Drawing on archival documents discovered in the Stasovs family archive (from the manuscript department of the Institute of Russian Literature) and in the secret archive of the Third Department of His Imperial Majesty's Own Chancery (from the State Archive of the Russian Federation), including correspondence of D. V. Stassov with the chairman of the Yekaterinoslav criminal court chamber, A. S. Kuznetsov (1862–66), the publication reveals the unknown pages of the history of the judicial reform of 1864 in the Russian Empire. The sources highlight the activities of the commission for preparation of the reform under (initially) quite difficult conditions. The details of the judicial reform preparation are given against the background of constant struggles between conservative and liberal camps (with the gradual switchover of high-ranking officials from one camp to another, depending on the Emperor’s will), as well as between different groups and directions. Thus, the adoption of final decisions was delayed due to uncertain, evasive position of its members, as it happened during discussions of individual bills in the State Council. Attention is drawn to the reaction of officials of the Third Department, when perlustrating letters of the Councilor of State, Chief Secretary of the Governing Senate and Chairman of the Criminal Court Chamber of Yekaterinoslav containing quite immodest thoughts on the “behind-the-scenes preparation” of the Judicial reform. D. V. Stasov’s letters were actually weekly diary entries recording the preparation of the 1864 judicial reform, his tone picturesque, descriptions of ministers and high officials accurate and caustic. Such evidence from very authoritative sources provides a wealth of material on the attitude of the Imperial Court and the heads of state institutions (the Ministry of Justice, the State Council, the Senate, the Committee of Ministers, the Second Department of His Imperial Majesty's Own Chancery) involved in decision-making concerning judicial projects, which has not been adequately covered in historical and legal studies. Publication of D. V. Stasov's letters (from the archival materials of the Stasov family fond) can significantly expand the source base on the history of preparation of the judicial reforms in the Russian Empire in 1860–64.