Lithium metal is the most promising candidate as anode of next generation’s rechargeable battery due to its high theoretical specific capacity(3884mAh/g) and the lowest redox potential(-3.04V vs SHE), so it could be applicable for high energy density required industry such as electric vehicles, drones, energy storage system, etc. However, Li metal has the challenges which should be solved before commercialization. It generates Li dendrite during plating/stripping and results in low coulombic efficiency by making dead Li and severe safety issue through internal short. In this paper, we develop the method to suppress Li dendrite by introducing polymer layer of high sulfur contents which could modulate stable SEI layer without harmful effect on cathode. Polymer is polymerized by inverse-vulcanization method between monomer and sulfur. Sulfur contents of this polymer can be regulated by reaction ratio of monomer and sulfur. On the pp separator, polymer layer is laminated and Li-Li symmetric cell was fabricated with this separator. Even with high current density and areal capacity, cycle life of cell is greatly improved. Moreover, Li / LFP cell shows higher capacity retention compared to reference and LiPS containing cell.