The current work was studied the interaction of genotype   environment for alfalfa seed yield. The split block design in three replications used for this study. Five sowing dates of 10^th October (D₁), 10^th November (D₂), 10^th December (D₃), 20^th March (D₄) and 20^th April (D₅) were used. Seed yield was taken in the second year in the beginning of March, April and May for studied sowing dates. The genotype plus genotype by environment interaction (GGE) biplot analysis was done. The obtained results showed that the environments exhibited high contribution in the total sum of squares for seed yield/plant (SYP) and seed yield/m² (SYW) in values of 60.69 and 60.80%, respectively, which accounted ten times of genotypes contribution. PC1 and PC2 were significant factors as revealed from GGE-biplot analysis and explaining 40.23 and 21.36% for seed yield/ plant and 37.04 and 17.83% for seed yield/m² in total sum of squares, respectively. According to the GGE-biplot analysis, the genotype G9 was the highest seed yield and stable genotype across environments and the environment E₄ (sowing at 20^th March) was yielded the highest seed yield/ plot which recorded 66.06 g.