An ultrasonic diagnostic apparatus that performs an image signal generating operation with respect to an ultrasound signal transmitted to and reflected from a target through a host computer and a control method thereof are provided. The ultrasonic diagnostic apparatus includes a probe including at least one transducer to transmit an ultrasound signal to a target, to receive the ultrasound signal reflected from the target, and to transduce the received ultrasound signal into an analog signal, an analog-to-digital (A/D) converter to convert the analog signal output from the probe into a digital signal, a compression unit to compress the digital signal output from the A/D converter, and a host computer to decompress the digital signal compressed by the compression unit and to perform beamforming.