The main objective of this investigation was to study gene effects by the analysis generation means for grain yield and its components characters in two bread wheat crosses, (Sids1 x Giza171) and (Shandaweel1 x Sakha94). Randomize complete block design with three replications was used for P1, P2, F1, F2, BC1, and BC2 during 2018/2019, 2019/2020 and 2020/2021 growing seasons. The measurements of gene effect and non-allelic interaction in addition to heterosis, inbreeding depression and heritability of grain yield and yield components in bread wheat were estimated. Scaling test showed significant effect for almost characters in both crosses. The additive (d) gene effect was positive and highly significant for number of kernels/spike and grain yield/plant for the first cross and positive significant with 100-kernel weight in the second cross, but negative significant with first cross. Estimates of dominance (h) effects were highly significant for number of spikes/plant and number of kernels/spike in second cross. Better parent heterobeltiosis, significant and highly significant heterobeltiotic effect positive was found between crosses for grain yield in two crosses and number of kernel/spike for the second cross. Results of inbreeding depression were highly significant positive for all the study traits. Broad sense heritability values ranged from 45.15 to 88.01% for all studied characters in both crosses.