Lithium-Sulfur (Li-S) battery has been a hot research topic currently due to its potential of combining high energy density and low cost together.  In this work, we have investigated various transition metal sulfides (CuS, FeS₂, TiS₂, CoS₂) as conductive additive to sulfur electrode in lithium-sulfur (Li-S) battery. We found that all metal sulfides additives enhanced the utilization of sulfur cathode at high rate discharge when compared with a sulfur-carbon composite electrode with equivalent sulfur volumetric loading. Systematic study suggests the reason for the enhancement is the activation of the polysulfide to Li₂S₂/Li₂S conversion process that constitutes the second plateau in Li-S battery discharge. Besides, the results also indicate that the high electronic conductivity of transition metal sulfides could not fully account for the second plateau activation. Instead, it is found that the interaction between polysulfide and metal sulfides is actually helping the nucleation process of Li₂S₂/Li₂S nucleation and deposition, and the level of this interaction also has profound influence on the cycle life and columbic efficiency of sulfur electrodes with transition metal sulfide additives. The results of this study will help to direct the design of non-carbon based conductive fillers for sulfur electrodes and enable the development of high power Li-S batteries.