A series of theta-shaped poly(tetrahydrofuran), poly(THF), of different molecular weights were effectively synthesized by an electrostatic self-assembly and covalent fixation process using a three-armed, star telechelic precursor having N-phenylpyrrolidinium salt groups carrying a trimesate, 1,3,5-benzene tricarboxylate, counteranion (1/trimesate). Under appropriate dilution in acetone, theta-shaped poly(THF)s (2) were obtained in 40-49% isolated yields through the covalent conversion of an electrostatic self-assembly of a single polymer precursor unit with retaining the balance of the charges between cations and anions. The isolated product was unequivocally characterized by means of H-1 NMR, IR, SEC as well as a reversed-phase chromatography (RPC), and MALDI-TOF MASS techniques.