To provide a composition for a lithium ion conductive electrolyte and a production method of a lithium ion conductive electrolyte achieving high ion conductivity and good cycle characteristics.

The composition for a lithium ion conductive electrolyte contains, as essential components, a multifunctional monomer, a salt monomer composed of an ammonium cation having a polymerizable functional group and an organic anion having a polymerizable functional group, a plasticizer, and a lithium salt. High ion conductivity and excellent cycle characteristics are achieved by adjusting the viscosity of the composition at 25°C to be 0. 5 to 10.0 (mP s).