This study was conducted to make a linear regression equation for conversion of pear fleshfirmness measured with 5mmΦ plunger into kg/8mmΦ unit. After drawing scatteric matrix with 2 typesplungers tested with 2,503 fruits harvested in 2013, we got a significant regression equation Y(caculatedkg/8mmΦ) = 2.35639 × X (measured kg/5mmΦ) + 0.51904. The R square value indicated that 87.6% ofvariance in conversion kg/5mmΦ into kg/8mmΦ can be explained. For verification of this equation, itwas converted from hardness(kg/5mmΦ) of 36 cultivars harvested in 2012 to kg/8mmΦ. In the result of42 cultivars T-test, most of them showed no significant difference in except for 6 cultivars ‘Seolwon’,‘Chuhwangbae’, ‘Pyeongchang soohyangli’, ‘Pyeongchang keumsakli’, ‘Conseiller a La Coeur’, ‘JumboLa France’. This equation seemed to be essential for method standardization of characteristics evaluationand also to be able to use at industrial company where made a hardness tester.