The effects of reactive monomer concentration on electro-optical properties were investigated using polymer-stabilized blue phase (PS-BP) liquid crystals (LCs) with different reactive monomer concentrations but identical chiral dopant concentrations. We found that the driving voltage was increased with increase in the reactive monomer concentration, whereas the switching hysteresis and Kerr coefficient were decreased with increase in the reactive monomer concentration in PS-BP LCs with identical chiral dopant concentrations. In addition, we found that the activation energy of electro-optical rising time was increased with increase in the reactive monomer concentration, whereas that of electro-optical decay, time was slightly decreased with increase in the reactive monomer concentration in PS-BP LCs.