Prediction of biotic invasions and/or invasive behaviour of alien species are important for management of introduced alien species (prevention, quarantine). The concept of invasion potential in plants is based on biological, physiological and ecological traits which pre-determine invasive behaviour of the introduced species in new areas and their success in invasions. Estimation of the potential is complicated because invading species are very heterogeneous group of organisms, detailed comparative studies are rare or absent, methodology used for estimation of invasive potential is far from reality. Theory of plant invasiveness is in very beginning. Several approaches/possibilities to estimate invasion potential for plant species to be introduced are discussed. The studies are oriented to the phenotypic plasticity, growth, reproduction, diaspor production, colonisation abilities, short- and long-dispersal. In second part of the paper limits of the IPIS estimations are discussed, including lag-phase, genotype changes after introduction, hybridization. Invasion potential is only one of important factors, which are responsible for biotic invasions, such as environmental conditions in new areas, namely climate, invasibility of natural communities, landscape invasibility, disturbance of natural vegetation, presence or absence of bio corridors facilitated long-dispersal yan invader, ecological window, species idiosyncrasies etc.