This investigation was carried out to evaluate eighty top-crosses and two checks SC-155 and TWC-324 at Experimental Farm, Faculty of Agriculture, Al-Azhar University at Assiut Branch. The obtained results exhibited highly significant differences among top-crosses and lines as well as, between two testers and the interaction of lines x testers for all studied traits, except number of days to 50% silking and number of rows/ear for testers. Significant desirable GCA effects were found in some lines for all studied traits. The tester SC-128 was significantly the best general combiner for ear length, 100-kernel weight and grain yield/plant, while the tester TWC-324 was significantly the best general combiner for plant height, ear height. Significant desirable SCA effects were found of some top-crosses for all studied traits. The variance due to GCA-L was higher than GCA-T for all studied traits, indicating that most of GCA variance was due to lines. The variance of SCA exceeded the variance of GCA (average) for all the studied traits, indicating that the non-additive gene action played an important role in the inheritance of all the studied traits. The lines contributed with the large percentage and played the major role in the inheritance of all studied traits. On the other hand, the testers contributed with the smallest percentage and played the lowest role in the inheritance of all studied traits.