A semiconductor memory device includes a memory cell array including a plurality of memory cell rows; and a data control circuit configured to, sequentially read a first unit of data from N memory cell rows of the plurality of memory cell rows, generate merged test results by comparing bits read from the first units of the N memory cell rows, and output the merged test results, during the test mode of the semiconductor memory device. Therefore, test time for testing the semiconductor memory device may be greatly reduced because a test device may determine pass/fail of the data of the unit of repair unit on one read operation.