The present invention relates to an electrolyte containing a polydopamine and a lithium-sulfur battery including the same and, more particularly, to a technique in which polydopamine contained in an electrolyte adsorbs a lithium polysulfide eluted from a positive electrode of a lithium-sulfur battery. When using an electrolyte, according to the present invention, to which polydopamine particles are added, the polydopamine particles dispersed in the electrolyte act to adsorb lithium polysulfide eluted from a positive electrode during the charging and discharging, and thus can suppress the diffusion thereof, i.e., suppress a shuttle reaction, thereby improving the capacity and lifetime characteristics of the lithium-sulfur battery.