A binder for preparing a positive electrode of a lithium-sulfur secondary battery, a composition including the binder, a positive electrode including the composition and a lithium-sulfur secondary battery including the positive electrode. The binder includes an acrylic polymer, and the acrylic polymer includes a unit formed from a hydroxyphenyl-based monomer or a disulfide-based monomer. The acrylic polymer may include 1 to 20 wt. % of units formed from the hydroxyphenyl-based monomer. The acrylic polymer may include 1 to 20 wt. % of units formed from the disulfide-based monomer. Such a battery has increased long-term stability due to suppression of leaching of the sulfur-based materials by absorption of lithium polysulfides.