Strong protonic acids constitute a very important group in the fast developing field of non-aqueons solvents. One can mention a few like sulphuric1, chlorosulphuric2, fluorosulphyric3 and disulphuric acids and liquid hydrogen fluoride1 as strong protonic acids or these, liquid hydrogen fluoride and sulphuric acid have been investigated quite extensively. Daring the last few years, investigations on fluorouslphuric and disulphuric acids have been undertaken In view of the fact that perhaps they are the strongest acids known. The present review Is an attempt to give a brief account of the work that has been accomplished in disulphuric acid.