The Zapotitlán de las Salinas Valley located in the South Western portion of the Tehuacán-Cuicatlán Valley, harbors a high plant diversity with a high proportion of endemism. In this study we describe the different plant communities along an altitudinal gradient between 1350 to 1700 meters above the sea level, in the vicinities of the Cerro Cutá, emphasizing on the differential species distribution among communities (? diversity). The plant communities description was conducted considering the different geomorphic surfaces (slopes with different Iithologies, altitudes and aspects, alluvial deposits along the Salado River and flat zones on the top of hills) and they were described by means of field samplings analyzing their structure and composition . The vegetation-type diversity is associated to soil and lithological heterogeneity in the study site producing a mosaic of plant communities in which a total species turnover of 71.3% indicates a high number of species restricted to different vegetation types. This high ? diversity contributes to the high regional diversity (y-diversity) reported for the Zapotitlán Valley.