Piao chicken is a Chinese native chicken breed,lack of caudal vertebra,pygostyle,tail feather and preen gland are the typical features of Piao chicken. The anatomy study was made in juvenile chicken. Rumples chicken and normal chicken were markedly different. There was no preen gland under the tail skin. The specimen of chicken skeleton stained with alizarin red and alcian blue showed,rumpless chicken had less tail vertebra than normal chicken,but the skeleton stained method was unsuitable for observing a large number of chicken samples. X-ray image technology was tried in this study,the coccyx could be observed clearly in the X-ray picture of rumpless and normal chicken. It′s convenient to observe chicken coccyx using X-ray image technology,especially for a large number of samples. The result of genetic study showed that rumpless trait in Piao chicken segregated in hybrid offspring from hybrid trmpless male chicken crossing with normal female chicken,and it′s a autosomal dominant trait. Rumpless chicken could be used as a valuable model organism for the study of vertebral dysplasia.