An approach to study the relation among the decentralization of the State, models of paradiplomacy, and the influence of subnational units in the construction of foreign policy. To this end, a comparative study of the paradiplomacy of Jujuy province and Shanghai city is proposed, in order to explain its impacts on national foreign policies of Argentina and China. The research will take a ten-year period, in accordance with the first decade of the Belt and Road Initiative (BRI) and the end of Argentine President Alberto Fernández's administration in 2023.