Sea ice, as one of the most important components of the Arctic climate system, is a sensitive indicator of climate variability and change.Present global warming is amplified in the Arctic region and recent studies both from observations and model results reveal the accelerated sea ice decline in the Arctic region.Located along one of the two pathways of Atlantic Water (AW) entering the Arctic, the Barents Sea (BS) communicates with both warm Atlantic Ocean and cold Arctic Ocean through water mass, heat and sea ice exchange.There is still a debate on the mechanisms controlling the sea ice interannual variability in Barents Sea.In this study, we employed the Finite Element Sea Ice-Ocean Model (FESOM), which is developed at Alfred Wegener Institute for Polar and Marine Research, to find out which mechanism proposed in the debate plays the dominating role.