Some aspects of physico-chemical behaviour of thermotropic liquid-crystalline (LC) polymers with mesogenic side groups (comb-shaped polymers) are considered in connection with the peculiarities of their molecular structure. The relationship between molecular parameters, such as molecular weight and molecular weight distribution of LC polymers and their thermal and phase behaviour are examined. The unusual mesophase types formed by such polymers and dynamics of their orientation in magnetic field are analyzed. Thermo- and photooptical phenomena in comb-shaped LC polymers related to their potential application as optical data storage are described.