Background and Aims: The xerophytic scrub in Mexico covers 40% of its surface and is the largest of all vegetation types. In Aguascalientes, it occupies 21.52% of the territory and has a strong degree of impact due to human influence. The objective of the study was to determine the floristic composition of herbaceous plants in two subtypes of xeric vegetation and to know the years of abandonment and type of crop that was planted, with the purpose of comparing the frequency and diversity of herbaceous plants in sites with primary and secondary vegetation in agricultural areas. Methods: Floristic inventories were conducted in crasicaule thornscrub and grassland with bushes, in sites with primary and secondary vegetation located in agricultural areas. The number of taxa was determined, the frequency of herbaceous species, alpha diversity (D0), Shannon-Wiener (H'), Simpson (D) and Pielou equity (J') indices were calculated. A comparative analysis of the diversity indices was also carried out. Key results: Two hundred nineteen species herbaceous species belonging to 140 genera and 45 families are reported. In the sites with primary vegetation Bouteloua chondrosioides was the most frequent species and in secondary vegetation Eragrostis mexicana. The primary crasicaule thornscrub has the highest richness with 138 species and H'=3.49, the least diverse is the secondary crasicaule thornscrub with 98 species and H'=2.92. The primary crasicaule thornscrub has fewer dominant species with D=0.05 and J'=0.83, while the primary grassland with bushes and secondary crasicaule thornscrub have more dominant taxa with D=0.10 and J'=0.74 in both conditions. Conclusions: In the xerophytic vegetation of Aguascalientes, the herbaceous stratum has a medium diversity index; its composition, frequency and diversity are directly affected by agricultural impact. The information generated in this study can be used in the restoration of arid areas impacted by agriculture.