ENThis contribution deals with a Latin letter that Andrzej Rudomina wrote in Hangzhou on 31 July 1627 to the Jesuit provincial of the Lithuanian province in Vilnius Fr. Michael Ortiz (ARSI, Jap. Sin. 161 II, fol. 98). Apart from the contents of this letter, the fact that it was written in Hangzhou at that date has some significance, because some modem sources hold Rudomina's arrival in Macau in 1626 (without specifying the month) and then tell us that he almost immediately went to Fuzhou, the capital of Fujian, in order to assist Giulio Aleni there. Actually he went to Fuzhou only at the end of 1628. [...] The books that Rudomina sent in 1627 apparently did not stay in Lithuania, or even never arrived there. Maybe all of them were transferred, or directly sent, to the General Archives of the Jesuits in Rome some time before 1676. In Nathanael Southwell's bibliography of Jesuit authors (Bibliographia Scriptorum Societatis Iesu, 1676), there is a list of Chinese titles (titles mentioned only in a Latin translation) that at that time were already present in the General Archives of the Jesuits in Rome. One of these titles is the copy of de Pantoja's book in which Rudomina's letter of 1627 was found. [p. 291, 293].