This study was carried out on the histological structure of the proventriculus during pre and post hatching periods. The primordial of the proventriculus was appeared at three day post incubation and was appeared as closed tube with star shape lumen. The primordial epithelium was stratified columnar epithelium, and then the number of the epithelium layers was decreased to become columnar epithelium at 8 days post incubation. Compound tubuleoalveolar gland extends from the star shape tube at 4days post incubation which was lined with mass of stratified epithelium and represent the glands. The glands were developed, branched and occupy the propria submucosa of the gland by age advanced and were lined by mucous cells and cuboidal cells. The mesenchymal cells that surround the primordial tube were differentiated to be the next propria and submucosa of the proventriculus at 11 days post incubation periods. The myoblast cells in the surrounding mesenchymal cells were differentiated to inner circular and outer longitudinal smooth muscle fibers of the tunica musclosa. The tunica serosa was appeared and clearly arranged at 9 days post incubation. The histological structure of the proventriculus post hatching had the same feature of the late pre hatching period except there was increase in the size of the gland and increase in the surface area of the glands