The synthesis and characterization of a new organic solvent soluble benzobisthiazole-thiophene copolymer based on alternating benzobisthiazole and oligo-3-octylthiophene units in the backbone, poly (benzobisthiazole-alt-3- octylquarterthiophene) (PBTOT) has been demonstrated. Differential scanning calorimetry (DSC) showed a melting peak (Tm) at 367 °C and recrystallization (TO) at 356 °C for PBTOT-2 and slightly lowers melting transition for PBTOT-1. The π-conjugated polymer semiconductors are of broad interest for applications in organic electronics and optoelectronics including field-effect transistors and photovoltaic cells. The enhanced interchain interactions in PBTOT include the much higher melt transition temperature and improved field-effect charge transport compared to P3OT.