The subantarctic islands provide a suite of environments and scenarios that give key opportunities to improve understanding of the consequences of climate change and biological invasions on terrestrial ecosytems. Anthropogenically-related invasions and temperature changes, amongst the most rapid worldwide are well documented in Kerguelen Islands and have profound impacts on indigenous biota. Here, we present an overview of the vulnerability of the terrestrial communities in French subantarctic Islands to two interacting factors: climate change and species introduction. We focussed on three invasive insects: one carabid beetle, one fly and aphids. By collating the data collected by our research group since 1974, coupled to the data we found in the literature, we addressed: (1) Dynamic of species introductions, including the study of the distribution and abundances of the invasive species, (2) Effects of climate change on the impact of invasive species on native communities, Vulnerability of the native communities, including ecological and evolutionary consequences of biological invasions.