The present invention discloses a charge-sharing type pixel structure having a first sub-pixel and a second sub-pixel that each includes a transistor. The second sub-pixel further has a third transistor and a top-gate electrode. When the third transistor is switched on, original gray scale applied to a liquid crystal capacitor of the first sub-pixel varies due to charges being shared with other capacitors. The top-gate electrode change the threshold voltage of the third transistor according to biasing signal so as to further adjust the variation of the gray scale voltage applied to the liquid crystal capacitor of the first sub-pixel.