New analogues of nifedipine, as a known calcium channel blocker, were synthesized by replacing the orthonitrophenyl group on position 4 with 1-(4-Nitrobenzyl)-5-imidazolyl or 2methylthio-1-(4-Nitrobenzyl)-5-imidazolyl substituent. Effects of the new synthesized compounds on blood pressure were studied at 15, 30 and 60 min after administration by indirect tail-cuff method and compared with nifedipine in male rat. The results indicate that all compounds reduce mean systolic blood pressure but their effectiveness is less than nifedipine. The onset of action of compounds 6c ,6d ,6e and 6g is also slower than the parent drug.