Aphids are generally considered as a major pest of corn. Thus, yield losses due to aphid infection can be considerable. Rhopalosiphum padi - the birdcherry oct aphid seems to be prevalent aphid species on maize in Korea. Aphid resistance of 91 Fls was assessed at two locations in Korea. In studies of combining ability for aphid resistance to different locations, GCA mean square was 4.48 times grater than that of SCA mean square. Thus, additive gene action was more important than that of non-additive gene action to aphid resistance. In two locations, inbreds 2, 4, 5 and 10 had negative GCA effects for aphid resistance.