Provided is directed to a circuit for controlling data and a data strobe driver in a semiconductor memory device, including: a first delay unit for outputting a data signal with a variable delay; a DQ driver for outputting a data signal according to the data signal passed through the first delay unit and a driver select signal; a second delay unit for outputting a data strobe signal with a variable delay; and a DQS driver for outputting the data strobe signal passed through the second delay unit by being driven according to the driver select signal.