Two new series of thermotropic, cholesteric copolymers were synthesized, and their thermal properties and cholesteric characteristics were studied by differential scanning calorimetry, by use of a hot-stage on a polarizing microscope, and by visual observation of the melts on a Fisher-Johns melting point apparatus. The copolymers prepared had either a combination of aromatic ester dyad and triad or a triad containing central trans-1,4-cyclohexylene unit and mixed spacers consisting of (+)-3-methyl adipoyl structure and either a polymethylene or 1,3-bis (carboxypropyl) tetramethyl disiloxane moiety. The change in the iridescent colors of the cholesteric polymers could be explained, at least, qualitatively based on the dependence of pitch on the two variables : composition and temperature. A couple of cholesteric polymers reported in the study has particularly low melting points about 50℃ and showed visible iridescent colors upon melting.