1. A pixel array, comprising: M*N pixels, each row of the pixels having a plurality of pixel sets, wherein the alternating pixel sets j and the (j+1) from the beginning to the end of the i th row of the pixels substantially have different driving polarity, wherein all of the pixels in the j th pixel set of the i th row of the pixels substantially have same driving polarity, and all of the pixels in the (j+1) th pixel set of the i th row of the pixels substantially have same driving polarity, where M, N, i and j are positive integers; the alternating pixel sets j and the (j+1) from the beginning to the end of the (i+1) th row of the pixels substantially have different driving polarity, wherein all of the pixels in the j th pixel set of the (i+1) th row of the pixels substantially have same driving polarity, and all of the pixels in the (j+1) th pixel set of the (i+1) th row of the pixels substantially have same driving polarity; the j th pixel set of the i th row of the pixels and the j th pixel set of the (i+1) th row of the pixels substantially have different driving polarity; and the (j+1) th pixel set of the i th row of the pixels and the (j+1) th pixel set of the (i+1) th row of the pixels substantially have different driving polarity; a plurality of data lines for respectively providing a corresponding pixel voltage, wherein all of the adjacent data lines provide pixel voltages having opposite polarities to each other, respectively; and a plurality of gate lines, wherein r th gate line is used for turning on only all odd pixels in the j th and the (j+1) th pixel sets of the i th row of the pixels and only all even pixels in the j th and the (j+1) th pixel sets of the (i+1) th row of the pixels, where r is a positive integer.