The article presents the methodological assumptions in functional approach for exploring the economic impact of national parks on the local economy. The original model of systemic analysis proposed and discussed in the article allows the broad spectrum of direct and indirect economic relations of national parks with their immediate spatial surrounding to be analysed. The discussion on the economic aspects of national parks’ operation relates to the specic conditions of Poland’s transition economy. The factors determining the economic function of a national park in the local economy include legal regulations which specify the powers of the park’s managing body and regulate the park’s behaviour on the local market; the attractiveness of the park’s location as a tourist destination; the scale of growth and commercialisation of tourism. Also important is the local social and economic context in which the national parks are embedded. Endogenous and exogenous determinants of the operation of Polish national parks determine the dynamic nature of their local economic relations.