To reduce the air resistance of the shaft part of a rowing oar in order to increase the speed of a racing boat.

In a rowing oar used supporting a middle part in a row lock 20 attached to a boat body to be turned around a vertical axis, a thin and long shape correcting body 30 linear-shaped in its cross section so as to cover the shaft part 11 of an oar main body 10 rotated around its axis is provided. A row lock side lever 40 and a shape correcting body side lever 41 extended in rear directions are provided in the row lock 20 and the shape correcting body 30, the tip parts of both levers 40 and 41 are connected to each other so as to be disconnected by a connecting member 42, and the longitudinal direction of the cross section of the shape correcting body is always held nearly lateral even if an oar main body 10 is rotated. The row lock side lever 40 is elastically supported in the row lock 20 so as to be swung and, for the shape correcting body 30, a tab 38 is provided in the rear edge of its tip part and if the tip part of the shape correcting body is sunk, an incidence angle is increased and the tip of the shape correcting body is easily pulled up from the water.