Dwarf French bean (Phaseolus vulgaris L. cv. Prince) and Swat corn (Zea rnays L. cv. First of all) F1 hybrid seeds were stored in 79% r.h. at 25oC for 92 days. The seed germination decreased with increasing storage period. They were completely non germinable after 92 days of storage. The loss in seed vigor were parallel to loss in seed germination. The vigor loss was more rapidly than viability loss. The loss of electrolytes from corn seeds increased significantly with increasing storage period. This increase of leakage from corn seeds was highly correlated with loss of vigor and germination. It also found that the seeds increased in moisture content during the storage process due to water uptake from the atmosphere. These might indicate that the membrane deterioration under high seed moisture content was involved in the vigor and viability loss of storage com seeds.