A method to control a memory cell in a memory device, where the memory cell includes a switch, a memory element and a negative resistance device coupled in series, the method includes: determine whether the memory cell is in a read operation or not; during the read operation in the memory cell, apply a read voltage greater than a predetermined threshold voltage of the negative resistance device for making the negative resistance device entering into a negative resistance state. A memory device that includes a memory cell array is also provided.