A series of asymmetric and symmetric bent-shaped molecules with branched terminals were synthesized and characterized. Their effects on inducing blue phase and electro-optical performances were compared and analyzed experimentally. It was found that the asymmetric and symmetric compounds almost have the same effect on inducing and stabilizing blue phase, but the electro-optical performance of mixtures doped with asymmetric compounds are much better than that of mixtures doped with symmetric compounds for they have a totally different dielectric anisotropy which can contribute to a larger Kerr constant.