The monosubstituted ferrocene derivatives containing biphenyl group in mesogenic one, omega-[4-(4-methoxybiphenoxy carbonyl) phenoxycarbonyl]alkyl 4-ferrocenylbenzoate, have been synthesized by changing the carbon atoms number of the flexible spacer. The analogous compounds in which phenyl group was contained instead of biphenyl one have been prepared and reported previously. Their phase transition behavior has been studied by a differential scanning calorimeter and a polarizing microscope. The effect of an existence of the biphenyl group on their phase transition behavior and a comparison of the phase transition phenomena with that of omega-[4-(4-methoxyphenoxy carbonyl) phenoxycarbonyl]alkyl 4-ferrocenylbenzoate will be discussed.