OVULATION CAN BE regulated by group of genes, termed as  fecundity (Fec) genes. The aim of this study was to identify genetic polymorphism in Booroola (FecB) gene in Barki, Rahmani, and Ossimi sheep breeds with different physiological status diagnosed by ultrasound. Accordingly, animals were early classified into three groups: carrying single fetus, twin fetuses and non-pregnant by ultrasonographic examination. Demonstration of fetal number was available as early as Day 35-40 post-mating transrectally, and trans-abdominally then after. The fetal viability could be checked through heart examination with M-Mode. Genomic DNA was extracted from blood samples of total number of sheep and two primers were used to amplify 190 and 140 bp fragments of FecB gene. The amplified fragments were digested using AvaII restriction enzyme. All sheep groups were non carriers for the FecB mutation and gave a 190 bp band (++) and 140 bp band (Fec++) for primer 1 and 2, respectively.In conclusion,no genetic polymorphism was detected in the three Egyptian sheep breeds in relation to pregnancy with single or twin fetuses. The study could be continue to search for other major genes.