A memory array structure and a method for forming the same are provided. The memory array structure comprises: a substrate; a plurality of memory cells, each memory cell including a vertical transistor, of which a gate structure is formed in a first trench extending in a first direction; a plurality of word lines in the first direction, each word line formed in the first trench; a plurality of bit lines in a second direction, each bit line formed in lower sides of a semiconductor pillars; a plurality of body lines in the first direction, each body line having a first portion formed on the gate electrodes and a second portion covering a part of a top surface of semiconductor pillar for providing a substrate contact to vertical channel regions; and a plurality of data storage device contacts.