Protected Areas provide a valuable source of information on the effects of invasive alien species on biodiversity and ecosystem functioning as well as the dynamics of invasions. Solidago canadensis is an extremely aggressive alien species. It is included into the world's 100 most invasive plant species. Our study aimed to monitor the invasiveness of S. canadensis in the Sanctuary «Prilepsky» in Minsk district. The article contains a brief description of the introduction of Solidago canadensis in Europe and more detailed in Belarus. The parameters characterising its invasiveness (average shoot length, foliage projective cover, average number of vegetative shoots, average number of generative shoots of S. canadensis and the average number of associated species per study plot) have been measured in three plant communities of the Sanctuary «Prilepsky» (Minsk district, Belarus) in 2016 and 2018. We noted that the invasiveness of S. canadensis is linked to the amount of sunlight received by ecotope. The proposed control measures include the afforestation of the open parts of the Sanctuary «Prilepsky» using native tree species, multiple mowings, and destroying the plants directly at the areas of most concern by volunteers.