A novel thiolane polymer, poly[1,2,4,5-tetrakis(propylthio)benzene] (PTPB), was synthesized by facile oxidative-coupling polymerization, characterized by FT-IR, XPS, XRD, TGA and EA, and tested as cathode active material in rechargeable lithium batteries. The FT-IR, XPS and elemental analysis confirm the occurrence of polymerization and show the existence of C–S–C bonds. The results show that the thiolane polymer has electrochemical activity as cathode material in lithium batteries and thioether bonds may be the centers of the electrode reaction. A maximum specific capacity of 200 mAh g−1 was obtained and this agrees roughly with the theoretical prediction. In addition, high voltage efficiency was obtained first time from sulfide polymer.