Disclosed are a pyrrolidinium type sulphonated zwitterion, a method of preparing the same, a lithium salt prepared by using the same, a method of preparing the salt, an electrolytic composition containing the salt and a lithium secondary battery including the electrolytic composition. Since the pyrrolidinium type sulphonated zwitterions prepared according to the invention are thermally and electrochemically stable, the lithium salt prepared by using the same exhibits a lower hygroscopicity than the conventional lithium salts and strong thermal and electrochemical stabilities. When the lithium salt of the invention is dissolved in an organic solvent independently or together with the ionic liquid, excellent conductivity and electrochemical stability are exhibited. Accordingly, the lithium salt of the invention is very suitable for the electrolyte of the lithium secondary battery.