A series of mesogen-jacketed liquid crystalline polymers, poly {2,5-bis[(4-alkoxybiphenyl)oxycarbonyl]-styrenes} (P-Cm, m = 8, 10, 12, 14 and 18) were designed and successfully synthesized via free radical polymerization. The chemical structures of the monomers were confirmed by H-1 NMR, C-13 NMR and Mass Spectrometry. The molecular characterizations of the polymers were performed with H-1 NMR, GPC and TGA. The phase structures and transitions of the polymers were investigated by the combination of techniques including DSC, POM, temperature-variable FT-IR spectroscopy, 1D WAXD and SAXS. The experimental results suggest that the polymers with symmetry mesogenic core containing two biphenyls can develop into a well-defined smectic A (S-A) phase. This implies that MJLCPs molecules shape can be modulated from rod-like to ribbon-like by simply changing the length of the mesogenic group. (c) 2013 Elsevier Ltd. All rights reserved.