The present article analyzes the air transport behavior of an airport network from the point of view of concentration / dispersion (higher / lower hierarchical differentiation) in a context of post-liberalization of air transport. As a case study, for the application of the analysis methodology, the case of Colombia is used, where liberalization of the aviation industry began in 1991. During the study period, 1992-2014, the most important airports were privatized, there was a release of air fares, and new air operators entered the market. The most important results of the present investigation indicate a situation of concentration of the connectivity in a few nodes (airports) of the network.