A driving shank assembly includes a tube, a drive head, a connector, and two quick release nuts. The tube has two enlarged portions each having a mounting recess and an external thread. Each of the enlarged portions has a plurality of slits and a plurality of elastic clamping pieces between the slits. The drive head has a driving recess and a mounting shaft. The mounting shaft of the drive head is inserted into the mounting recess of the tube. The connector has a mounting shaft and a connecting shank. The mounting shaft of the connector is inserted into the mounting recess of the tube. The connecting shank of the connector has a retaining groove for mounting an actuating tool. Each of the quick release nuts has an internal thread screwed onto the external thread of the tube.