The present invention relates to a terphenyl dihalide monomer having sulfonate groups and a process for preparing the same. More particularly, the present invention relates to a terphenyl dihalide monomer having sulfonate groups prepared by a process comprising obtaining a terphenyl dihalide derivative by Suzuki cross-coupling of a tetrahalobenzene and phenylboronic acid and introducing sulfonate groups into the phenyl rings at each end of the terphenyl dihalide derivative, the resultant monomer capable of being prepared into a polymer electrolyte having superior ion conductivity through nucleophilic aromatic substitution (S.sub.NAr) polymerization due to the presence of two halogen atoms and two conducting sulfonate groups in the monomer molecule, and a process for preparing the same.