This paper deals with the seismic activity of Koyna region during the period Sept., 93 to Aug., 96. The data was recorded by • single component seismograph iastalled II Vikram Sarabhai Bhavan, Anushaktinagar, Mumbai. A coda-duralion magnitude scale has been developed through regression analysis of data set comprising 49 earthquakes ‘for which Me ~ reported by India Meteorolollical departmeat. An empirical relationship, LoIIOE. – 13.18 + 1.2332 Mo ,to estimate eDerIY release has alsO been developed. The total amount of energy released during this period was estimated to be 1.7 x 10″ eras. Half-yearly variation of b- value has been cIiscussed in the end.