Recent two moderate earthquakes (2016 Mw=5.4 Gyeongju and 2017 Mw=5.5 Pohang) in Korea provided the unique chance of developing a set of relations to estimate instrumental seismic intensity in Korea by augmenting the time-history data from MMI seismic intensity regions above Ⅴ to the insufficient data previously accumulated from the MMI regions limited up to Ⅳ. The MMI intensity regions of Ⅴ and Ⅵ was identified by delineating the epicentral distance from the reference intensity statistics in distance derived by using the integrated MMI data obtained by combining the intensity survey results of KMA (Korea Meteorological Administration) and ‘DYFI (Did You Feel It)’ MMIs of USGS. The time-histories of the seismic stations from the MMI intensity regions above Ⅴ were then preprocessed by applying the previously developed site-correction filters to be converted to a site-equivalent condition in a manner consistent with the previous study. The average values of the ground-motion parameters for the three ground motion parameters of PGA, PGV and BSPGA (Bracketed Summation of PGA per second for 30 seconds) were calculated for the MMI=Ⅴ and Ⅵ and used to generate the dataset of the average values of the ground-motion parameters for the individual MMIs fromⅠ to Ⅵ. Based on this dataset, the linear regression analysis resulted in the following relations with proposed valid ranges of MMI.