A manufacturing method of a liquid crystal display device having a liquid crystal layer between a pair of substrates. The method includes disposing between the pair of substrates a liquid crystal composition including liquid crystal molecules and a polymerizable compound that is polymerizable by active energy rays or a combination of active energy rays and heat, and polymerizing the polymerizable compound by active energy ray irradiation, or by both active energy ray irradiation and heat with and/or without applying voltages to the liquid crystal layer, so that a polymer formed by the polymerizing process decides an alignment of the liquid crystal molecules when no voltage is applied. The amount of active energy ray irradiation is decided so that at least some of the polymerizable compound remains in the liquid crystal layer after the polymerization process. Further the amount of the polymerizable compound that remains is not more than a predetermined value.