The codex, annexed to the Vol. 757-CA-AR from the Biblioteca Nacional de Antropologia e Historia, Mexico, was transferred to the Escuela Nacional de Conservacion, Restauracion y Museografia for conservation purposes. By using optical microscopy, it was determined that the support was made of maguey fibers (agave). Due to the rare origin of this native paper, this opportunity was used to develop a description of the support, and a condition report. Also a bibliographic research was carried out in order to find more codices made with the same material, obtain information about the manufacture techniques and the use of agave as a raw material in Mexico. It was possible to define the geographic area, and the manufacture period of the document, reduce the number of species that could have been used for its elaboration and determine the differences between amate and maguey papers, both about their features and alterations. This information leads to recognize and to value this type of supports.