The invention relates to a TFT-LCD array substrate and a making method thereof. The array substrate comprises a gate line, a data line, a thin film transistor, a pixel electrode and a common electrode line, wherein the gate line, the data line and the thin film transistor are formed on the substrate, and the pixel electrode and the common electrode line form a storage capacitor, a pulse electrodeis arranged between the common electrode line and the pixel electrode and is used for enabling the storage capacitor to have a first capacitance value when the pixel electrode is started to be charged and enabling the storage capacitor to have a second capacitance value when pixel electrode charging is finished, and the first capacitance value is smaller than the second capacitance value. In the invention, because the pulse electrode is arranged between the common electrode line and the pixel electrode, on the one hand, the storage capacitor has the smaller capacitance value when pixel electrode charging is started so as to lower load of the thin film transistor and enhance the charging capability of the thin film transistor, and on the other hand, the storage capacitor has the larger capacitance value when pixel electrode charging is finished to strengthen the holding property of voltage of the pixel electrode and lower the leaping voltage of the pixel electrode at the moment that the thin film transistor is closed.