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 (S-A phase), as shown by (HNMR)-H-1 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 (T-g) of LC-PS was much lower than that of PVPDMS, while the clearing point (T-i) of LC-PS significantly increased compared with M.