La Pratica della Mercatura by Venetian Merchants Arata MORI This research note introduces and examines the contents of two commercial manuals which had been compiled by Venetian merchants in the 14th century: Zibaldone da Canal and Tarifa zoe noticia dy pexi e mexure di luogi e tere che s’adovra marcadantia per el mondo, and considers their common features as Venetian type. The commercial manual is a genre of historical documents by Italian merchants in the late Middle Ages, they had mainly been compiled by merchants of the cities in the northern-central Italy by the 15th century. In the late Middle Ages, Italian merchants, who had been engaged in the international trade, handled a large quantity of information and knowledge of distant markets in their work. Manuals had been compiled by putting such commercial records in order for the purpose of referring them and handing down to younger merchants easily. However, in spite of the common purpose of compilation, there are two different types of manuals: according to the study of Ugo Tucci, one is Florentine libro, and the other is Venetian tariffa. Two Venetian manuals examined in this research note are anonymous: the Zibaldone is a memorandum or a notebook of young merchant in the beginning of the 15th century, and the Tarifa is composed of two manuals. Both of them had not been compiled systematically by one merchant, rather, they had been compiled gradually by several merchants. The lack of intention of well-organizing is the common feature of Venetian manual, Venetian merchants had regarded convenience as more important thing than coherence as one book, or libro, compared with Florentine one. It is supposed that these differences between manuals had been caused by the differences of situations of commercial activities, and had also reflected the social positions of merchants in each city.