The invention provides an array substrate and a liquid crystal display device. The array substrate comprises a glass substrate, a shading metal layer, a first insulating layer, a thin film transistor, a pixel electrode layer and a common electrode layer, wherein the shading metal layer is arranged on the glass substrate, and is provided with a first area and a second area; the first insulating layer is arranged on the glass substrate and the shading metal layer; the thin film transistor is arranged on the first insulating layer, and is provided with a source, a drain, a gate and a semiconductor layer; the pixel electrode layer is electrically connected with the drain; the common electrode layer is electrically connected with the shading metal layer, and forms first storage capacitance with the pixel electrode layer; the first area of the shading metal layer is used for shading, and the second area of the shading metal layer is opposite to the drain to form second storage capacitance between the second area of the shading metal layer and the drain. The array substrate and the liquid crystal display device have the beneficial effects of increasing the storage capacitance of the liquid crystal display device and further improving display performance.