This study was conducted at Al-Qassim Green University, Collage of Veterinary Medicine, Anatomy and Histology Branch. The experiment was designed to study the uterus of awassi sheep fetuses where take (16) samples sheep fetuses in prenatal stages are distributing into two groups: (second and third trimester of gestation) according to the gestational age, which is determined depending on the crown rump length (CRL) and divided into group I at (90) days of gestation and Group II at (140) days of gestation, containing (8) fetus each group to record the developmental changes in the uterus. In the first group (90) days the uterus appear muscular tubular organ and small in size with thin translucent wall composed of a short body and two short pointed uterine horns that highly attachment with uterine body and finally uterine cervix that has about (5-6) incompletely developed primitive folds that continuous directly with vagina while histological appear uterus wall composed of four undeferential the inner lining epithelium, sub- epithelium layer, primitive musculares layer and outer sub-musculares layer and lumen appear tubular irregular wide comparatively with the next stage. In the second group (140) days, appear the uterus more differentiation and development than pervious stage that appear tubular organ small in size relatively with thick wall comparatively with second trimester of gestation, composed of short uterine body and two short pointed uterine horns and finally uterine cervix that has about (5-6) rings folds connect directly with vagina, While histological, the uterine wall consists of four layer more differentiation: the inner lining epithelium, pluripotential blastemic tissue layer, muscular layer and outer serosa layer, the lumen less wide and deepest portion of the internodular areas expanded parallel with the nodular surface.