Intense cyclones have become more frequently observed in the Arctic, with obvious links to the occurrence of Arctic extreme events. The increase in cyclone activity may also strengthen atmosphere-sea ice-ocean interactions to further amplify long-term Arctic climate change. Therefore, an imperative question to answer is: how have Arctic cyclones changed and how will they change in the future? While previous studies have suggested intensification of Arctic cyclone activity, inconsistencies have also emerged when using different analysis metrics and analyzing different datasets. In this study, we employed an improved, integrative index based on our previous work (Zhang et al., 2004) to analyze variability of and changes in Arctic cyclone activity. The index aggregates information on cyclone frequency, intensity, and duration. The data we used are 6 hourly sea level pressures from the NCEP-NCAR, ERA5, and JRA-55 reanalysis products for the period 1950-2021. We utilized a recently further refined cyclone identification and tracking algorithm. The integrated results from the three reanalysis datasets indicate that Arctic cyclone activity has continued to intensify during recent decades. Dynamic mechanism analysis suggests that increased lower troposphere baroclinicity in the Arctic and changes in the large-scale upper tropospheric/stratospheric circulations jointly contributed to the cyclone intensification.