Total carbon content coefficients were generated for basal biomass units for each of the components (stem, branches, small branches, leaves and bark) of trees and shrubs species in three areas with different historical use (traditional agriculture, extensive foraging and clearcut) on tamaulipan thornscrub, which will allow estimating carbon stored in this type of ecosystem. The total carbon content expressed as a percentage of biomass was determined with the Solids TOC Analyzer equipment that analyzes the total carbon contents in solid samples by complete combustion. By an ANOVA, we found a highly significant interaction between components and species; thus proving that the total carbon content of biomass components depends on the species. Highly significant differences were found among the components of all the species; the stem component (45.93 ± 0.18 %), branches (45.73 ± 0.17 %) and small branches (45.70 ± 0.19 %) showed similar behavior in the total carbon content; demonstrating differences when Tukey test was used, where the highest value (48.14 ± 0.30 %) was presented by the carbon content of leaves and the lowest by bark (42.08 ± 0.21%).