In a group of purebred Arab mares the level of inbreeding and its effect on three body conformation traits was determined. Moreover, estimated were heritability coefficients of the traits and their phenotypic,genetic and environmental trends. Considered were conformation records of 706 Arab mares born in the years 1936- 1993. The mean inbreeding level of mares was 0.88%. No considerable effect of inbred rate on body conformation traits was found. The obtained partial regression coefficients were close to zero. Heritability coefficients appeared low and amounted to 0.160 (±0.078) for height at withers, 0.052 (±0.067) for chest circumference and 0.050 (±0.054) for circumference of cannon.Negligible positive genetic trend was observed for all the traits studied, whereas the environmental trends were not clear.