This article presents results of the study of exotic woody plants producing selfseeding on the territory of St. Petersburg (Russia). According to our data, selfseeding is recorded in 227 species of 73 genera of 31 families in St. Petersburg. In 49 species of 28 genera of 19 families, selfseeding is observed for the first time. A number of species have potentially invasive properties, which is especially notable in recent years against the background of climate warming in St. Petersburg. Selfseeding emergence and maintenance depends on a number of factors, such as the presence of group plantings, level of soil turfing, degree of illumination, and presence or lack of treatment. It is urgent to constantly monitor all species producing self seeding, since some of them may be potentially invasive.