Using the NCEP/NCAR monthly mean tropopause pressure and temperature reanalysis data from 1979 to 2002,we have investigated both the interannual and interdecadal variabilities of the wintertime tropopause.The tropopause pressure index is defined as the areal average over the region where the tropopause pressure variability reaches its maximum.The tropopause temperature index is defined in a similar way as for the tropopause pressure index.Results show that the global tropopause pressure and temperature averaged over 24 years increased with the increase of latitude.However,the distributions of the tropopause pressure and temperature in the tropics and the high latitudes were relatively homogeneous.The globally mean tropopause pressure and temperature were descending during the winters from 1979 to 2002,and these results agree with the results from part of sounding data.The subtropics in the Northern Hemisphere was the region where the maximum tropopause variability is found,while the tropopause variability reached its minimum in the low latitudes.The periodicities of pressure and temperature indices are found to be dominantly the 13 years and 3-6 years.There was prominently positive correlation between the tropopause pressure and temperature in the most of world,while the correlation between the tropopause pressure and tropospheric mean temperature was significantly negative in the most of world.