Liquid crystalline block copolymers that incorporate both PHTH-6 mesogenic units and polycarbonate (PC) segments in the main chain were synthesized by polycondensation in solution of hydroxyl-terminated PC and acid-chloride-terminated PHTH-6. The copolymer compositions were determined from H-1-NMR data. The structure, thermal properties, as well as liquid crystalline behavior of the block copolymers were characterized by H-1-NMR, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), transmission electron microscopy (TEM), and X-ray scattering, etc. A novel kind of morphology of a liquid crystalline block copolymer, a feathery structure, was observed for the first time, in which the PHTH-6 mesogenic microphase dispersed in the PC microdomain in the form of feathery structure. These block copolymers showed a microphase-separation system, for which the geometry on a length scale changes from tens of nanometers to 600 = and the degree of phase separation was strongly dependent on the segment lengths incorporated.