The present disclosure provides a pixel array and a fabrication method thereof. The pixel array includes a plurality of gate lines and a plurality of data lines which are arranged intersected and insulated and a pixel unit disposed at a position where each of the plurality of gate lines and each of the plurality of data lines are intersected. The pixel unit includes a thin film transistor (TFT). The width-to-length ratios of channels of the TFTs are sequentially increased in such a manner that the width-to-length ratios of the channels of the TFTs in the pixel units positioned in a same row (and/or a same column) are sequentially increased along a scanning direction of the gate line coupled to gate electrodes of the TFTs in the same row (and/or along a data writing direction of the data line coupled to the source electrodes of the TFTs in the same column).