It is crucial to investigate the traits of tomato (Solanum lycopersicum L.) seeds in order to move toward the commercial production of promising hybrid seeds from the Desert Research Center's Plant Breeding and Conservation Program. In the summer months of 2023 and 2024, the research began up. At the greenhouse program at Saint Catherine (28°33ˋ N, 33°56ˋ E, and 1650 m above sea level) of South Sinai, five lines were crossed with three tomato testers using manual pollination to develop hybrid seeds and self-pollination to generate parental seeds. The experimental design was randomized complete block design with three replicates. The results indicated that the sources of variation in line x tester analysis were significantly different for most measured traits in the two seasons. L₃ and L₄ were the best of most of the traits. The cross L₄ × T₂ was the best for the number of seeds per fruit and average seeds weight per fruit. The crosse L_{2 ×} T₁ was positive heterosis and heterobettiosis for all traits. The proportional contribution lines were higher than line × tester interactions and testers for 1000 seeds weight trait, because it basically reflects seeds weight of lines. Heritability estimates in narrow sense were low for all the studied traits.