Provided are a liquid crystal display device and a manufacture method thereof. The liquid crystal display device is a blue phase liquid crystal display device. The alignment layer is not required. The liquid crystal composition forming the liquid crystal layer comprises liquid crystal material, quantum dots material mixed in the liquid crystal material, polymeric monomer and chiral material; the polymeric monomer is polymerized to form a polymer network under a blue phase temperature range as forming the liquid crystal layer, which can stabilize the blue phase liquid crystal, and thus to expand the blue phase temperature range. The grain size of the quantum dots material in the liquid crystal composition is in the nano scale, which can expand the blue phase liquid crystal temperature range. Namely, the blue phase temperature range of the liquid crystal material has already been expanded before the polymeric monomer is polymerized.