The aim of this study is to estimate weaning weight (WW) using six body measurements (withers height (WH), body length (BL), chest circumference (CC), leg circumference (LC), body depth (BD), and width of chest behind shoulders (WCS)) measured at weaning period by factor scores in multiple regression model. For this aim, a total of 94 Norduz lambs were used. "Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy" and Bartlett's test of sphericity were used to determine whether factor analysis was suitable for data studied. According to results of these criteria, the data was found to be most appropriate for applying factor analysis. Three factors whose eigenvalues greater than 1 were selected as independent variables for multiple regression analysis. It was concluded that that three factors had significant-positive effects on weaning weight and all three factors explained approximately 80% of variation in weaning weight.