A method of manufacturing an LCD device includes forming a gate bus line, a gate insulating layer, an active layer, and a source/drain metal layer on a transparent insulating substrate; etching the source/drain metal layer and active layer to form a source/drain electrode and a channel layer while forming a metal protection pattern in a peripheral region of the transparent insulating substrate; forming a protection layer and a pixel electrode on the insulating substrate; forming a main seal line at an interior region of the array substrate, forming a first auxiliary seal line between the metal protection pattern and the main seal line, and forming second and third auxiliary seal lines; and attaching a color filter substrate to the array substrate via the main seal line.