ten advanced yellow maize inbred lines were topcrossed to two inbred lines testers at Giza Agricultural Research Station in 2013. Resulting 20 topcrosses a long with two standarad check hybrids were evaluated for grain yield and some agronomic traits at three locations, i.e., Sakha, Mallawy and Ismaelia Agricultural Research stations during 2014 growing season. Analysis of variance indicated significant mean squares due to crosses for days to 50 % silking, plant and ear heights and grain yield. The Inbred lines; GZ-656, GZ-658, GZ-661 and GZ-662 were high general combiners for grain yield. Among the crosses, four test crosses (GZ-654x078, GZ-656x078, GZ-660x021 and GZ- 661x078) were found to possess positive significant SCA effects mean while better mean performance for grain yield. Negative and significant SCA effects were also observed in two crosses (GZ- 654x021 and CML-121x078) for number of days to 50 % silking.