Abstract: [Objective] The research aimed to analyze the correlation between the body size indices and body weight of adult female yak of Jiali and further predict the regression analysis of body weight,so as to guide the production practice and breeding work of Jiali Yak.[Method] Based on the body size data of 64 Jiali adult female yaks measured in Jiali County of Tibet,the correlation coefficients between the body weight and body height,body length,chest circumference and cannon circumference of Jiali adult female yaks were analyzed.At the same time,the regression model of the body weight of adult female yaks were further analyzed and predicted.[Result] The correlation coefficients between the body weight and body height,body length,chest circumference and cannon circumference of Jiali adult female yaks were 0.887,0.828,0.807 and 0.712 respectively.The test results showed that the correlation between the body weight and body height,body length,chest circumference and cannon circumference reached extremely significant level（P0.01）.Three regression models for forecasting the body weight were obtained.The correlation coefficients between the predicted value and measured value were 0.854,0.787 and 0.843.[Conclusion] The body weight of Jiali adult female yaks showed significant linear correlation with the body height,body length,chest circumference and cannon circumference.