Over the last couple of years economists have developed tools to identify strategic industries, productive linkages, chains, and agglomeration economies. The Input-Output model (I-O model) is widely used to explain the behavior of the economic structure at a disaggregated level. This study seeks to address the economic structure of Tamaulipas through the subsectorial regionalization of the 2013 I-O model given by INEGI, using the Flegg, Webber and Elliott approach. The results show buy-sell input inter-sectorial relationships among Tamaulipas' economic industries, required for intermediate consumption. A symmetric matrix is obtained, breaking down gross production values per industry, through regional inter-sectorial flows of money. A cross nature descriptive analysis is developed, with limitations on secondary source information available. The study finds 11 key sectors in the state that promote regional development given conditions of high agglomeration, and dependency through chains of production. [ABSTRACT FROM AUTHOR]