Variation in the Arctic Ocean stratification will exert a tremendous impact on the Arctic Ocean sea ice, circulation, water mass variation, and even global climate change. In the past, due to limited observational data and conditions, there was little awareness of the stratification in the Arctic Ocean, especially the hydrological characteristics of the subsurface.Strong stratification, which is found in the most of the Arctic Ocean, prevents vigorous AW ventilation. This ventilation in the western Nansen Basin leads to the reduction of sea-ice thickness. In the past, these conditions have been limited to the western EB, because winter ventilation of AW in the eastern EB was constrained by stronger stratification there. Therefore, studying on the phenomenon of halocline ventilation is very significant for comprehending sea ice conditions.Based on the ocean reanalysis data ORAP5 of the European Center for Medium-Range Weather Forecasts (ECMWF), the multi-scale temporal and spatial changes of the upper ocean stratification in the Arctic Ocean basin are statistically analyzed. The multi-scale temporal and spatial variation of the upper ocean stratification in the entire Arctic Ocean basin are statistically analyzed.In our research, we propose a new criterion to identify halocline ventilation. According to this criterion, we describe the ventilation phenomenon of the Eurasian basin in detail, and reveal its variation and relationship between the depths of halocline.