Accurate external characters determination of horses and keeping its records regularly is important to preserve the phenotypic structure of selection in Arabian horses and to guide selection programs. In this context, the aim of this study was to determine the external characteristics in Arabian mares of different age groups raised in Sultansuyu Studfarm. For this purpose, 18 mares included in the 3-4 age group, 14 mares for in 5-6 years old, 19 mares for in 7-8 years old, 16 mares in 9 years old and over, and 67 mares in total were evaluated in terms of body measurements, coat color, and markings. In the study, forehead width was 17.76±0.07, head length 55.04±0.040, neck length 52.87±0.17, cidago height 159.07±0.18, waist height 156.65±0.19, croup height 158.10±0.15, body length 161.53±0.32 and tail length was 97.38±0.52, anterior shin girth was 19.15±0.17, thorax girth was 176.93,±0.93 and thorax depth was 93.88±0.22. Statistically significant differences were found between age groups in terms of forehead length (P<0.05) and thorax depth (P<0.001). There was no statistical significance among other body measurements (P>0.05). The highest coat color observed in mares were chestnut (64.18%), followed by gray, buckskin (16.42%) and black (2.98%). In 31.34% of the mares, there were no facial markings, faint star in 28.36%, star in 16.42%, blaze in 8.95%, irregular star in 7.46%, apron face in 4.48%, and several white hairs on the forehead in 2.98%. Also, when the mares are evaluated in terms of nose and leg markings; interrupted stripe and bald face, pastern were found to be numerous. Breeding studies are carried out in a professional manner without changing the phenotypic characteristics of Arabian horses in Sultansuyu Studfarm.