On the basis of letters from the collection No. 342 of the Manuscripts Department of the Russian State Library (RSL) the co-operation of the famous Russian antiquarian book dealer of the late 19th — early 20th century P.P. Shibanov with the members of the House of Romanov in the field of formation of their personal libraries is studied. The study was carried out with the aim of obtaining reliable information about the editions offered to complete the personal libraries of the Imperial House. On the basis of previously unexplored sources the assortment of P.P. Shibanov’s booksellers, presented for purchase to the members of the Imperial Family, is revealed. The letters from the Shibanov collection of the RSL were received by the bookseller from high-ranking officials of the courts of the grand dukes and grand duchesses, and in some cases directly from members of the dynasty. The material gives an idea of the spheres of intellectual predilections of the Romanovs, of their interest in rare and ancient editions, among which were books of the 17th—18th centuries. The prices for books indicated in the letters are of no small importance. Among the information about the booksellers’ assortment offered to the Romanovs we should mention the books that for one reason or another did not interest the members of the dynasty during the preliminary acquaintance and were returned to the bookseller.In the course of the research, the drafts of P.P. Shibanov’s letters to the Moscow Governor-General, Grand Duke Sergei Alexandrovich, were revealed, and the exchange of telegrams with the Pushkin enthusiast, Prince Oleg Konstantinovich of Imperial Blood, was analyzed.Most of the letters were received from the court offices of the Grand Dukes Nikolai Mikhailovich (a famous historian), Konstantin Konstantinovich and Pyotr Nikolayevich (through the court office of the latter the sending of books to his wife, Grand Duchess Militsa Nikolaevna, for familiarization was discussed).The letters we have identified cover mainly the late 1890s — early 1900s; the latest are a telegram from Prince Oleg Konstantinovich of Imperial Blood, received by P.P. Shibanov in 1913, and a letter from the court office of Grand Duke Konstantin Konstantinovich in 1915.The studied letters reveal the book assortment offered by P.P. Shibanov to the members of the Imperial Family and the book preferences of the Romanovs, but do not indicate whether these books were purchased by them.