Forty Local Awasi sheep fetuses were collected from several areas in Nineveh Governorate, further than local slaughter house. Their estimated ages calculated depending on crown-rump length with the aid of Richardson formula. The study aimed to detect the site and the time of appearance of centers of ossification in the bones of hind limb of Awasi sheep by using modified method of double stains to demonstrate cartilage with bone, or by using radiography. The first ossification centers appeared in the hind limb bones was the primary center of the tibia and femur, metatarsus with ilium then ischium at 45, 46, 48, 50, 52 days of fetal age respectively. The ossification centers of pes phalanges appeared in the following sequence; distal phalanx, followed by the proximal phalanx and end by middle phalanx, at 58, 60, 64 days respectively. Ossification centers of tarsal bones began to appear in calcaneus at 64 days, talus at 77 days, central and 4th tarsal bones at 96 days, followed by centers of 3rd and 2nd tarsal bones at 100 days while, the center of 1st tarsal bone appeared lastly at 105 days. Femur, tibia and metatarsus studied statistically by follow up the relative increase of their total lengths with ossified portion length of their diaphyses. The very important finding of our work is that the maximum relative increment in the length of the long bones and their ossified diaphysis is happening within the 7th to 8th weeks of gestation making this time to be considered as the most critical period for bone development especially long bones so it is essential to avoid giving any medication or therapy during that time which could affect or even retard this vital process.