A multi-level cell copyback program method in a non-volatile memory device is disclosed. The method includes performing a multi-level cell copyback program operation; performing selectively a first verifying operation, a second verifying operation or a third verifying operation in accordance with data stored in an MSB node of the first register or data stored in an LSB node of the second register. The first verifying operation is based on a first verifying voltage. The second verifying operation is based on a second verifying voltage higher than the first verifying voltage. And the third verifying operation is based on a third verifying voltage higher than the second verifying voltage. The copy back program operation is performed repeatedly in accordance with result of the verifying operation.