Two monosubstituted ferrocene derivatives, 8-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl]octyl 4-ferrocenylbenzoate (MPAF-8) and 9-[4-(4-methoxyphenoxycarbonyl)phenoxycarbonyl] nonyl 4-ferrocenylbenzoate (MPAF-9), were synthesized and their phase transition behavior was studied using a differential scanning calorimeter. a polarizing microscope and an X-ray diffractometer. MPAF-8 exhibited two liquid crystalline phases in both heating and cooling processes at approximately room temperature. In the heating process. a crystal-crystal phase transition behavior was ascertained. The phase transition behavior of MPAF-9 was very similar to that of MPAF-8 except for the behavior of the crystal-crystal phase transition in the heating process. In MPAF-B. one crystalline phase was transformed into another crystalline phase completely. On the other hand, this transformation was observed in part in MPAF-9, and as a result, the melting behavior was observed two times in the heating process.