Six inbred lines of maize (ART-B21,ART-B46,ART-B26,ART-B37,ART-B34 and DL.A3) were crossed with three testers DL.B3, DL.C3 and (DL.B3 x DL.C3)L3 using triple test cross system. Seeds of genotypes (lines, testers and crosses) weregrown in a randomized complete block design (RCBD) with three replicates, in autumn season 2012,
Todetect of hybrid vigor, and some genetic parameters for traits plant height, ear height, ear length, number of rows per ear, 250-grain weight and grains yield per plant using triple test cross. Results of statistical analysis showed that there were found significant differences among genotypes (parents and crosses) for all studied traits. The cross (ART-B37 x DL.B3) was the superior for number of rows per ear (18.60) and grains yield per plant (181.05g.plant-1). The cross (ART-B46 x DL.B3) gave the highest hybrid vigor in grains yield per plant (69.71%). Analysis of variance for epistemic gene action test indicated non-significant lines mean square for all traits that indicated the absence of epistasis except 250- grain weight. Additive variances was significant for all traits, except grains yield per plant was non-significant, while dominance variances wasnon- significant for all traits, except number of rows per ear was significant. These results showed that the additive genetic variance was more important, and this reflects on the average degree of dominance values which were less than one in all traits, except grains yield per plant which was over dominance. The broad sense heritability was more than 90% for all traits, while the narrow sense heritability was high for all traits, except grains yield per plant was lower. The negative simple correlation coefficients showed that there is increasing of dominant genes for ear height, number of rows per ear, 250-grain weight and grains yield per plant, while the positive simple correlation coefficients for plant heightindicated the reverse. It concluded that hybrid vigor is a quantitative trait results from the polygenes action that may act with dominance or partial dominance.