The present invention provides a heat dissipation structure of a portable ultrasonic diagnostic apparatus includes an external housing which includes a circuit portion accommodating space accommodating a circuit board inside one side and includes a battery accommodating portion for accommodating a portable battery therein inside another side, a plurality of circuit boards arranged in a vertical stacking structure from top to bottom inside the circuit portion accommodating space of the external housing, and a heat conducting pipe with one side disposed between the plurality of circuit boards and another side disposed in the battery accommodating space to absorb heat generated by the plurality of circuit boards and discharge the heat into the outside air through a vent formed at a place at which the battery accommodating space of the external housing is positioned.