This study was conducted at Seed Technology Research Laboratory, Sakha Agricultural Research Station, ARC, Egypt, during 2020 to 2022 years to elucidate seed germination%, seedling characters, EC, moisture content, seed index, crude protein, oil%, acidity% and free fatty acid of some cotton cultivars (Gossypium barbadense L.) due to different storage period and storage conditions. The chemical composition of the seeds with high oil content is related to specific processes occurring in the seeds during storage. In this trial, Giza45, Giza92, Giza94 and Giza96 cotton cultivars were submitted to accelerated aging for three and five days, and natural aging for six and 18 months, under controlled and conventional (non-controlled) conditions. Increasing accelerated aging period from 0 to 3 and 5 days caused decreased in germination%, seedling vigor, protein% and oil%. While, increased electrical conductivity, moisture%, acidity and free fatty acid. Generally increasing storage period reduced seed germination%, seedling vigor, oil% and protein%. While, increased electrical conductivity, moisture%, acidity and free fatty acid. Controlled conditions 42%RH gave the highest viability and seedling vigor during storage period up to 18 months compared to other storage conditions. Giza92 and Giza94 cultivars greater resistance to germination loss in artificial and natural aging than the other cultivars and gave the highest seed viability (as a results of the high seed germination%, lowest electrical conductivity, acidity % and free fatty acid). The losses of vigor, poor germination, weak and abnormal seedling are associated with an increase in the free fatty acids that produce deleterious effects on cell.