Twenty four white maize inbred lines were top crossed with two testers i.e. SC 162, SC 166 in 2009 growing season. Resulting 48 crosses in addition to two commercial check hybrids i.e. SC 162 and TWC 352 were evaluated at Sakha, Mallawy and Ismaelia Agriculture Research Station Farms during 2010 growing season.  Data were estimated on the following traits: silking date, plant height, ear height, grain yield, number of ears /100-plant, ear length and ear diameter. Mean squares for Lines (L), testers (T) and L x T interaction were significantly for all studied traits, except for grain yield and ear length of tester and for ear height and No.of ears/100-plant of L x T interaction. The best GCA effects for grain yield, number of ears/100-plant, ear length and ear diameter were obtained by inbred lines SK5001/1, SK5001/2, SK5001/6 and SK5001/9, respectively. Also, the inbred lines SK5002/12, SK 5002/19 and SK5002/19 showed better GCA effects for silking date, plant height and ear height, respectively. The tester SC162 showed the best GCA effects for grain yield, number of ears/100-plant, ear length and ear height. Moreover, the tester SC166 was the best combiner for earliness, shorter plant type and ear diameter. The best crosses for specific combining ability were SK 5001/6 χ SC162 for earliness, SK5002/20 χ SC162 for plant height, SK5002/22 χ SC166 for grain yield, SK5001/2 χ SC162 for number of ears/100- plant and SK5002/10 χ SC166 for ear length and ear diameter. The highest mean values of crosses for grain yield were obtained from the SK5001/1 x SC162 (33.67 ard. /fed.), SK5001/7 x SC162 (33.59 ard./fed.). These three way crosses outyielding significantly than the commercial hybrids TWC 352 (27.54 ard./fed.) and SC 162 (30.86 ard./fed.). The additive gene effects were more important for silking date, plant height, ear height, grain yield, No.of ears/100-plant and ear diameter. While, the non additive gene effects were important for ear length. Moreover, non additive genetic effects was more interacted by locations than additive gene effects for all studied traits.