To provide a lithium ion conductive electrolyte composition and a method of manufacturing a lithium ion electrolyte which develops a high ion conductivity and has a good cycle characteristic, one of the cell characteristics.

The lithium ion conductive electrolyte compound containing a monomer having a radical polymeric function group and a spiro-ring structure in one molecule, a plasticizer, and a lithium salt as necessary components has a viscosity of 0.5-10.0 mPa s at 25°C in the constant shearing velocity measurement. The method of manufacturing a lithium ion conductive electrolyte reacts monomer components of the lithium ion conductive electrolyte composition to polymerize them by irradiating with an active energy beam and/or heating. A secondary cell has a lithium ion conductive electrolyte obtained by the manufacturing method of the lithium ion conductive electrolyte composition.