Genetic variability and heritability are two important factors for plant improvement programs where the magnificence and type of this variability determine the selection criteria to be used by the breeder. This study aimed to estimate the genetic components associated with variance and covariance based on partial diallel crosses and factorial mating designs, as well as, to identify the association between yield components and other quantitative traits to extend an orientation for selec­tion. Six cowpea varieties were used in this study. All possible crosses were done according to partial diallel mating design in addition to the F₁ hybrid which were arranged in a factorial mating design. The parents, F₁ and their F₂ generations were evaluated in a field trial experiments at El-Baramon station, Dakahlia Governerate, in a randomized complete blocks design with four replicaties. The results revealed that both two mating designs were suitable to study the genetic parameters. The means of F₁ hybrids exceeded the mid parents (MP) and the better parent (BP). Significant values of heterosis were obtained for all studied traits. The highest values were 43.84% for pod length versus MP and 15.68% for number of pods per plant versus BP. The magnitude of both additive and non-additive genetic variances were high that means the possibility to development inbred lines of cowpea through selection. The higher values of broad-sense and narrow-sense heritability indicating good genetic variability for effective selection. The following traits; pod length, pod weight, weight of 100-seeds, and number of seeds per pod could be considered in breeding for grain yield, as they contribute significantly to its improvement.