A mother substrate assembly according to an exemplary embodiment of the present invention includes: a first mother substrate and a second mother substrate formed with a plurality of unit liquid crystal panels; and a sealant formed between the first mother substrate and the second mother substrate and combining the mother substrates, wherein the sealant encloses a circumference of each unit liquid crystal panel, and includes a first irradiation line formed in the sealant, and a second irradiation line formed in the sealant of a side closer to the unit liquid crystal panel than the first irradiation line.