Disclosed herein is a differential amplifier using body-source cross coupling. In a common gate differential amplifier in which common gate amplifiers are implemented in a differential structure, since the bodies of the common gate amplifiers are cross coupled to the sources of the opposite common gate amplifiers, it is possible to increase transconductance due to body effect to improve a gain. Since the potential of the body is equal to that of the source in a DC mode, a breakdown voltage reduction problem is alleviated.