Three series of 1,4-disubstituted butadiynes containing a tetrafluorophenylene in core structure have been synthesized from 1-pentafluorophenyl-2-trimethylsilyacetylene. The results showed that 1-phenyl-4-(4-n-alkoxyphenyl-2,3,5,6-tetrafluorophenyl)-butadiynes were nematic liquid crystals. However, 1-phenyl-4-(4-n-alkoxy-2,3,5,6-tetrafluoro-phenyl)-butadiynes and 1-(4-nitrophenyl)-4-(4-n-alkoxy-2,3,5,6-tetrafluorophyenyl)-butadiynes did not exhibit any liquid crystallinity. The IR spectra showed that the l-phenyl-C(4-n-alkoxyphenyl-2,3,5, 6-tetrafluorophenyl)-butadiynes were good liquid crystals for IR modulator.