A half diallel set of crosses involved eight maize inbred lines were evaluated in normal and artificial infection by borer at the Agricultural Research and Experiment Center, Faculty of Agriculture, Benha University, Egypt. To estimate combining ability, improve productivity of maize and resistant to borer Mean squares of environments, genotypes and its fractions as well as general and specific combining abilities (GCA and SCA) reached the significance level of probability for all traits. Low GCA/SCA ratios than unity were obtained for grain yield and resistance to borer characters in artificial infection environment and across environments. Therefore, non-additive type of gene action seemed to be more prevalent. Regarding to grain yield/ plant the crosses P3xP5, P3xP6 and P3xP8 had significant superiority over the check hybrid SC pioneer 30k8 under both environments. P3 ranked the first best inbred line in grain yield/ plant in both environments. The best combinations were P3xP5, P3xP6, and P3xP8 for grain yield/plant at both environments.