The present invention relates to a rudder for a ship including a rudder body installed in a hull to be rotatable in the rear of a propeller; and a rudder bulb installed in the rudder body, wherein the portside and the starboard side of the rudder bulb are configured to have an asymmetric shape and the rudder body is configured to have a streamlined shape which is bilaterally symmetrical, thereby reducing friction resistance of the rudder bulb against slip stream of the propeller and enhancing propulsion efficiency of the propeller.
