This publication presents the results of the archaeological studies relative to the settlement pattern, realized between 1983 and 1996 within the framework of the Michoacán Projects I and III led by the researchers of the Centre of Mexican and Centro-American studies (CEMCA). The Michoacán project (1983-1987) aimed at the realization of a study of all the perceptible demonstrations of the prehispanic occupations in the region. After the first three field’s seasons of the year 1983, dedicated essentially to survey and test pits, we directed all our efforts to the resolution of more specific objectives, the main objective being the settlement patterns study of the very numerous postclassical sites of the south region of the Project, located in the Tarascan Sierra and Malpais of Zacapu. The excavations directly connected to this subject were made in 1984 and 1985, but various test pits and surveys realized between 1983 and 1986 brought very useful data for the study. The author presented a doctoral thesis sustained in January 1991, in Paris I University on “The sites and residential and civic-ceremonial structures of the region of Zacapu, during the Postclassic”. This thesis constituted the first synthesis in French on this subject. As a consequence of the criticisms emitted during the defense of this thesis, and of insufficient data concerning the Early Postclassic occupation of the Zacapu Region, the Michoacán III (1993-1996) project was established. Both main purposes of this Project were the study of the transition between the Palacio phase (900-1200) and the Milpillas phase (1200-1450) as well as the systematic recording of sites and various structures of these sites localized in the Zacapu Malpais and dated from the Milpillas phase. This publication will present mainly the results of the surveys, surface collections and test-pits and allow inferences on the settlement patterns of the region of Zacapu and particularly the rapid growth in the Malpais of Zacapu of large sites at the beginning of Postclassic.