Greenhouse gases emissions related to soil organic carbon (SOC) are important in the study of changes in the terrestrial ecosystems. Simple operative models offer the opportunity to analyze the dynamics of alterations induced by land use change, vegetation and management practices. There are a reasonable number of studies reporting soil texture and SOC in Mexico that can be used to operate these simple models. The present study shows various alternatives for establishing parameters of the COLPOS model. This model was constructed to characterize the distribution of SOC in the physical fractions of the soil. The COLPOS model considers SOC in different soil pools: particulate organic matter (POM, labile organic matter) and organomineral complexes (organic matter + sand-silt-clay). Inert organic carbon (IOC), with mean residence times from hundreds to thousands of years and associated particle size, allow precise definition of the COLPOS model parameters and determination of potential SOC losses. Definition of these two parameters allows implementing the COLPOS model using only information on SOC and soil texture available in Mexico. The present approach to determine COLPOS model parameters was implemented from data obtained during physical soil fractionation after ultrasonic dispersion to ensure complete fractionation of soil.