ABSTRACT The study was conducted in Sirinka Agriculture Research Center and Debre Birhan Agriculture Research Center to phenotypically characterize and to assess the structural indices of local, F1 Local x pure Dorper 50% crossbreds and pure Dorper sheep. The study was performed based on body linear measurements and three hundred three (303) sheep were selected for this study. From the total samples 81, 128 and 94 sheep were local, 50% crosses and pure Dorper, respectively. The animals were grouped into three age groups based on PPI as (0 PPI, 1 PPI, and ≥2 PPI). A total of 17 linear body measurements and scrotal circumference for males were taken from each animal. The data were collected at two sites. The data for all local and all F1 Local x pure Dorper sheep were collected from Sirinka Agricultural Research Center and the data for pure Dorper sheep were collected from Debre Birhan Agricultural Research Center. General linear model of SAS 2008 was used for statistical analysis of the collected data. Breed, sex and age were the fixed effects considered for the analysis. Body weight and most of the linear measurements were significantly (P<0.01) affected by breed effect except chest depth, neck length and height at wither which are not significant (P>0.05). Sex had significant effect on body weight and all of the linear measurements except Rump width (P>0.05). Body weight and all the linear measurements were significantly (P<0.01) affected by age effects. Body weight had the mean value of 28.47±0.8kg1, 35.94±0.53kg and 46.65kg for local, crossbred and pure Dorper sheep respectively. 41.32± 0.68kg and 32.61±0.54kg were the mean value of body weight of male and female sheep respectively. Positive and highly significant (P<0.01) correlations were observed between body weight and most of the body measurements for all the three sheep breeds. The result of multiple linear regression analysis showed that chest girth explained more variation than any other measurements in both ewes (52%) and rams (78%) of local sheep, ewes (59%) and rams (86%) of crossbred sheep. The result of multiple linear regression analysis showed that chest girth explained more variation (86%) than any other measurements in Dorper rams. However, punch girth explain more variation (70%) in Dorper ewes. 10 Structural indices were calculated for the three sheep populations (local, F1 crossbreds and pure Dorper) separately. Body index, weight, thoracic development, body ration, height slop, length index, width slop, depth index, balance and pelvic index were used in the standard formula to calculate structural indices. Weight index scored the total mean value of 24.82kg, 26.61kg and 35.75kg for local, crossbred and pure Dorper sheep respectively. Thus, it can be concluded that pure Dorper and crossbred sheep exhibit meat type traits. It was suggested to observe the performances of pure Dorper and crossbreds in farmers’ management condition. Key words: Crossbred, Dorper sheep, Permanent incisor, Phenotype, Regression, Structural index