The territories exploited by major mining projects of the Amazonian of Pará, Northern region of Brazil, have caused socioeconomic impacts of different complexities and set to debate the role of mining as a tool for territorial planning in the host cities that house Major Mining Projects, for failing to create economic and social dynamics, making the multiplier effect of the Major Mining Projects an indicator of local development of the mineral economy in the municipalities of Pará. The main objective of this paper is to present the main impacts caused by mining activities in Pará municipalities. A documentary and bibliographical analysis was necessary for the textual elaboration, in addition to field research in the study area. We can observe that mining is an important productive activity, but has caused significant changes in Pará territory, as well as in economy and in the environment, and the way of life of local populations.