Abstract: A total of 40 150-day-old Hetian chickens (half male and half female) were randomly selected in the experiment to determine six body size traits (body length, keel bone length, depth of chest, width of chest, tibia length, and tibia girth) and seven slaughter performance indexes (live weight before slaughter, carcass weight, eight of eviscerated yield with giblet, eviscerated yield weight, breast muscle weight, leg muscle weight, and abdominal fat weight), and then the correlation analysis and principal component analysis were performed on these 13 indicators. The results showed that the body size traits of Hetian roosters were significantly higher than those of Hetian hens (P＜0.01). Except that the abdominal fat weight of roosters was significantly lower than that of hens, the slaughter performance indexes of roosters were significantly higher than those of hens (P＜0.01). In terms of correlation, there were different degrees of correlation between body size traits and slaughter performance of Hetian chickens, and there were some differences between genders. The body length, keel bone length, depth of chest and width of chest in body size traits were highly correlated with the live weight before slaughter, carcass weight, eight of eviscerated yield with giblet and eviscerated yield weight in slaughter performance, which showed significant (P＜0.05) or extremely significant (P＜0.05). In the principal component analysis, the character index of roosters could be simplified into 3 principal component slaughter factor, tibia girth factor and keel bone length factor, and the cumulative contribution rate was 80.231%, while the character index of hens was simplified into 2 principal component slaughter factor and tibia length factor, and the cumulative contribution rate was 78.245%. The study have shown that the correlation between body size traits and slaughter performance and the principal component analysis could provide data reference for the protection and breeding of the germplasm resources of Hetian chickens.