A line x tester analysis involving 28 top-crosses generated by crossing seven elites maize inbred lines (yellow) with four testers (yellow single crosses) was conducted for different some traits during 2015 cropping season at the Experimental Farm of Agricultural Faculty, Mansoura University, Egypt. The experimental design was the Randomized Complete Block Design (RCBD), with three replications. The objectives of this study were to estimate of general and specific combining ability effects of the parents (the inbred lines and the testers) and to evaluate the top-crosses performance of the hybrids for flowering, vegetative and ears yield plant^-1 traits. The GCA/SCA ratio was found to be less than unity in all studied traits under both conditions, except ear height under stress condition, revealing that non-additive gene effects were more important than additive gene effects in the expression of these traits. Results showed that line (1), line (2), line (6), tester (1) and tester (2) were the best general combiners among the parents for ears yield per plant. Top-crosses no. 3, 4, 7, 9, 13, 20 and 26 under both conditions, 10, 19, 21, 22, 27 and 28 under water stress condition and 14, 23, 24 and 25 under normal irrigation condition showed negative and highly significant specific combining ability estimates for tasseling date. Top-Crosses no. 3, 4, 7, 9, 10, 13, 20 and 26 under both conditions, 19, 21, 22 and 28 under water stress condition and 6, 8, 23, 24 and 25 under normal irrigation condition showed negative and highly significant specific combining ability estimates for silking date. Negative and significant or highly significant specific combining ability estimates were detected for top-crosses no. 1, 11, 16, 19 and 26 under stress condition for ear height. Significant or highly significant and negative specific combining ability estimates were detected for top-crosses no. 1, 6, 9, 16 and 20   under stress water condition and 7, 12 and 13 under normal watering condition for plant height. Highly significant and positive specific combining ability estimates were detected for top-crosses no. 3, 4, 10, 13, 17 and 24 under stress water condition, 1, 2, 9, 16 and 20 under normal water condition and 5, 8, 11, 15, 18, 22, 25 and 26 under both water conditions for ears yield per plant.