Several 2-alkylcarbamoyl-1-alkylvinylbenzo[b]furans were designed to find a selective leukotriene B-4 (LTB4) receptor antagonist. 2-(2-Alkylcarbamoyl-1-alkylvinyl) benzo[b] furans having a substituent group at the 3-position, 4-(2-alkylcarbamoyl-1-methylvinyl) benzo[b] furans having a substituent group at the 3-position, and 7-(2-alkylcarbamoyl-1-methylvinyl) benzo[b] furans and 3-(2-alkylcarbamoyl-1-alkylvinyl) benzo[b] furans were prepared and evaluated for LTB4 receptor (BLT1 and BLT2) inhibitory activities. (E)-3-Amino-4-[2-[2-(3,4-dimethoxyphenyl)ethylcarbamoyl]-1-methylvinyl]benzo[b]furan ((E)-17c) showed potent and selective inhibitory activity for BLT2. On the other hand, (E)-7-(2-diethylcarbamoyl-1-methylvinyl) benzo[ b] furan ((E)-27a) showed potent inhibitory activity for both BLT1 and BLT2.