The cross (Sids1 x Giza 168) of bread wheat was used. The analysis of gene effects was done using means of six populations, i.e. P1, P2, F1, F2, BC1 and BC2 on two sowing dates. The experiment was conducted at El –Mattaana Agricultural Research Station during three successive growing seasons (2017/2018, 2018/2019 and 2019/2020). For grain yield / plant, number of spikes/plant and 100-kernel weight, heterotic effects were significant and positive in the two sowing dates comparing with mid and better parent while No. of grains/spike was significant and positive in the first sowing date comparing with mid parent, as well as the biological yield/plant in the two sowing dates comparing with mid parent and in the second sowing date comparing with better parent. Significant and positive inbreeding depression was recorded for all studied characters in the two sowing dates except for the harvest index, these results for plant height can be utilized in breeding for semi-dwarfing. The additive type of gene action was significant and positive for the plant height, No. of spikes/plant and biological yield/plant in both sowing dates, No. of grains/spike in the second sowing date and grain yield / plant in the first sowing date, while dominance effects were significant and positive for plant height, No. of spikes/plant and biological yield/plant in both sowing dates, No. of grains/spike and grain yield / plant in the first sowing date. The (additive × additive) gene effects were significant for all studied characters, except for grain yield / plant in the second sowing date. The additive × dominance gene effects were significant for the plant height and harvest index in both sowing dates, No. of spikes/plant in the first sowing date and grain yield / plant in the second sowing date. The dominance× dominance gene effects were significant for the majority of traits, except for No. of spikes/plant and 100-kernel weight in the first sowing date. High to moderate heritability values in the broad and narrow sense were detected for all studied traits except No. of spikes/plant and biological yield/plant in the second sowing date and grain yield/plant in the first sowing date which had low values of heritability in narrow sense. The values of genetic advance as percent of the mean were high (25.78%) to moderate (19.99%) for all traits in both sowing dates except for the biological yield/plant in the late sowing date which was low (5.22%).These results showed the possible gain from selection as percent increase in the F3 over the F2 mean when the most desirable 5% of the F2 plants are selected.