Based on the NCEP/NCAR reanalysis monthly 2.5°×2.5°500 hPa heights and the Arctic 1°×1°sea ice data,the indices for the polar vortex area and intensity,and the Arctic sea ice area are calculated,and their longitudinal distributions,and periodicity and the sudden changes of long term trends are analyzed to reveal their intrinsic relationships.It is found that the indexes of sea ice and polar vortex had evident differences in longitudinal distribution,and their relative positions were also different in the eastern and western hemispheres.They had own individual periods,respectively,in addition to the common period of 4-month,quasi-6-month,quasi-one year,4—5-year and 10-year.It is also evident that both the Arctic sea ice and polar vortex aresa have decreased slowly since the 1980s,but the time when sudden change happened was not the same.The sea ice and polar vortex area indices were positively corrlated,but the relationships between the sea ice area and the polar vortex intensity,and between the polar vortex area and the polar vortex intensity were very complicated.