WT5BZ]In the context of NCEP/NCAR daily 500hPa geopotential height during Jun. to Aug. in 1998 investigation is conducted on the quantitative depiction of daily evolution for Eurasian blocking high.Evidence suggests that on the basis of deviations in heights from zonal mean three area indexes are calculated for the Urals, Lake Baikal and Ehuocik areas, respectively,which can well express the daily evolution in intensity and position for the 1998 summer Eurasian blocking highs and bear close relationship with the summer precipitation over China.