The invention provides a memory array. The memory array comprises a substrate, a plurality of word lines, a charge trapping structure, a plurality of trench channels and a plurality of bit lines. The word lines are located over the substrate and the word lines are parallel to each other. The charge trapping structure covers a surface of each of the word lines. The trench channels are located over the substrate and the word lines and the trench channels are alternatively arranged and each trench channel is separated from the adjacent word lines by the charge trapping structure. The bit lines are located over the word lines and each bit line is across over each of the word lines and each trench channel is electrically coupled to the bit lines.