A lithium-sulfur battery includes a positive electrode having at least one positive active material selected from the group consisting of an elemental sulfur, Li.sub.2S.sub.n (n.gtoreq.1), Li.sub.2S.sub.n (n.gtoreq.1) dissolved in catholytes, an organosulfur compound, and a carbon-sulfur polymer ((C.sub.2S.sub.x).sub.n: x=2.5.about.50, n.gtoreq.2), an electrolyte having salts of an organic cation, and a negative electrode having a negative active material selected from the group consisting of a material capable of reversibly intercalating/deintercalating lithium ions, a material capable of reversibly forming a lithium-containing compound by a reaction with lithium ions, a lithium metal, and a lithium alloy.