A TFT array substrate includes a substrate, at least one gate line and gate electrode, a gate insulating layer, and at least one channel component, source electrode, drain electrode and data line. The gate line and gate electrode are disposed on the substrate, wherein both of the gate line and gate electrode have first and second conductive layers, the first conductive layer is formed on the substrate, the first conductive layer contains molybdenum nitride , the second conductive layer is formed on the first conductive layer, and the second conductive layer contains copper. The gate insulating layer is disposed on the gate line, gate electrode and the substrate. The channel component is disposed on the gate insulating layer. The source electrode and drain electrode are disposed on the channel component, and data line is disposed on the gate insulating layer.