Abstract: In order to explore the correlation between body weight and body size of Kirgiz sheep, clarify the direct and indirect effects of body size on body weight, and study the linear regression relationship between body weight and body size, sixty Kirgiz sheep aged 210 days were selected as the study subjects in the experiment. The body weight and body height（X₁）, body length（X₂）, chest circumference（X₃）, tube circumference（X₄） and other body size indexes were measured, and the measurement results were analyzed by SPSS 19.0 software for correlation, path and stepwise regression analysis, and the optimal linear regression equation was established. The results showed that the body weight and body size indexes of male Kirgiz sheep were higher than those of female Kirgiz sheep, the difference of chest circumference was significant（P＜0.05）, and the difference of other indexes was extremely significant（P＜0.01）; the coefficient of variation of male and female body weight was more than 10.00%, and the coefficient of variation of other body size indexes was less than 10.00% except for ewe tube circumference; the body size indexes of male and female Kirgiz sheep were significantly positively correlated with body weight（P＜0.01）; the most direct effect on body weight was chest circumference（coefficients were 0.378 and 0.373 respectively）, and the most indirect effect on body weight was body height（coefficients were 0.501 and 0.530 respectively）; the optimal regression equation of body size index between body weight and body size index of male and female sheep was Y_male=0.484 X₁+0.552 X₂+0.446 X₃-61.858（R~2=0.787, P＜0.01）, Y_female=0.444 X₁+0.395 X₂+0.362 X₃-46.853（R~2=0.817, P＜0.01）. The results indicated that not only body weight selection should be taken into account, but also to the selection of body height, body length and chest circumference in the breeding process of Kirgiz sheep.