The paper introduces a simple method to synthesize novel liquid crystalline polystyrene (LC-PS) containing a mesogenic unit at a side chain by hydrosilylation through poly[(4-vinylphenyl)dimethylsilanol] (PVPDMS) and liquid crystal monomer cholesteryl 4-[4-(undec-10-enoyloxy)benzoyloxy]phenyladipate (M). The LC-PS had high purity, high molecular weight, narrow distribution, good thermal stability, and typical thermotropic liquid crystallinity (SA phase), as shown by 1H NMR analyses, size exclusion chromatography (SEC), thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction (XRD). The glass-transition temperature (Tg) of LC-PS was much lower than that of PVPDMS, while the clearing point (Ti) of LC-PS significantly increased compared with M.