Dynamic aging chain of the Czech Republic population

System dynamics is a method enabling simulation and subsequent analysis of various socio-economic problems. Even though it was founded about fifty years ago, it is relatively new and little used in the Czech Republic. It has a good practice to make use of molecules, standard partial modelling structures which make the modelling processes easier and more effective.The objective of this article is to introduce and provide such molecule of an aging chain for the Czech Republic population. To increase its usefulness the aging chain is disaggregated and divided into two chains, one for each sex. The aging chain molecule consists of stock and flow diagram, a system of differential equations and parameters quantified on the basis of demographic data for Czech Republic.Proposed model of aging chain also capture a special phenomenon of the Czech population - the postponing of motherhood and thus the increase in average age of mothers. This fact led to special model structure that is uncommon for existing aging chains of different populations.The model is constructed on the basis of official demographic data of the Czech Statistical Office and the results of the simulation are compared with the surveyed data. The intersection of data sources resulted into disaggregation of population into twelve age cohorts. The chain is created to serve as a molecule for more complex models. Therefore, variables functioning as interface for implementation into such models are indicated in the text.