A new ovarian cell line was established from pupae of Egyptian cotton leaf worm Spodoptera iiitoralis. cells were adapted at 270 and characterized at the morphological. growth. and keryotyping . The number of chromosomes was counted and compared with reference cell lines Sf9. Sl96 and with the number of chromosomes on eggs (in viva) oi the same source of insect. Cell doubling time was 24hr. Chromosomes were morphological typical to those described from other species of Lepidopterous. Chromosomes number was counted on 5? metaphases for the new cell line (SL omi) and it was ranged between 4-203 Chromosomes. As for 58 metaphases were prepared from eggs. the counted chromosomal number was ranged between 4— 24 on 57 metaphases and one only metaphase had 46 chromosomes. Obtained results from eggs chromosomes preparation and Si omi was different from those prepared from Sf9, which ranged between Bland 263 in 68 metaphase (Ref).