This study was conducted at Shandaweel Agricultural Research Station, ARC Egypt, during the three growing seasons from 2003/04 to 2005/06. Six bread wheat genotypes namely Giza164, Giza164, Sids1, Sids7, Sahka 93 and Debeira were crossed in all possible combinations, excluding reciprocals. The parents, F1,s and F2,s generations were sown on favorable and late sowing dates to explore the genetic behavior of some agronomic characteristics, study the type of gene action controlling the agronomic traits and identify the best combination under heat stress (Late sowing).The results indicated that Late sowing reduced plant height, spike length, days to heading and days to maturity by (13.61 and 7.07%), (6.33 and 5.66 %), (8.26 and 8.2%) and (9.8 and 8.9%) for F1 and F2 generations, respectively as compared with the recommended sowing. The earliest genotype in heading was (P5) Sids 7 under both sowing dates, while the most promising F2 populations were (P3×P6) and (P3×P5) under recommended planting and (P2× P5) and (P4× P5) under late planting. The results indicated that both additive and non-additive gene effects controlled the genetic system of plant height (cm), spike length (cm), days to heading and days to maturity. The additive gene effects were the most prevalent type under both sowing dates. The positive and negative alleles were unequally distributed among the parents for all traits under the two planting dates. The parents had more positive alleles for all traits in both generations under both sowing dates except in the F1 hybrids under late sowing for heading date and in F1 and F2 generations under late sowing for maturity date which exhibited more negative alleles. Heritability values were high in both broad and narrow-sense for these characters. The previous results revealed that selection could be effective for developing these traits in segregating generations.