A method for checking reading errors of a memory includes the following steps. A first data fragment is received. A first count index according to the first data fragment is generated, wherein the first count index is corresponding to a quantity of one kind of binary value in the first data fragment. The first data fragment is written into the memory. The first data fragment is read from the memory as a second data fragment. A second count index is generated according to the second data fragment. The first count index is compared with the second count index.