The current study was aimed to determine the onset of vertebral ossification, ribs, and sternum, and to evaluate ossification centers using the alizarin red and alcian blue staining techniques in the partridge embryos. One-hundred fertilized eggs of the partridge were placed in a hatching machine. From day 8 of incubation, three egg samples were randomly selected daily for staining until hatching. After staining, ossification centers in various parts of thorax were evaluated by a stereomicroscope. Data from examination of different thoracic parts of the partridge embryos indicated that cartilaginous thoracic vertebrae was were formed in the embryo on the 8^th day, but the ribs and sternum were not visible. Cartilaginous ribs were formed on the 9^th day of embryo. A cartilaginous sternum began to form on the 10^thday of embryo. On the 13^th day, cartilaginous uncinate processes were observed at the caudal border of embryonic ribs. From the 16^th day, the first ossification center was detected in the body of ribs. The embryonic development process was progressive on the 17^th and 18^th days. The first ossification centers in the embryo of the 22^nd and 23^rd days were detectable in the cranio-lateral process of sternum and in the uncinate process of the first thoracic rib, respectively. On the 25^th day, the cranio-medial process of sternum was the first ossification center in the embryos. The emergence of ossification centers in different parts of thorax and the developmental process were not observed at the pre-hatching time.