The objective of this study was to determine the INBREEDING depression on growth traits in Moghani sheep. Pedigree information of 8836 animals collected during the years of 1987 to 2006 by Moghani Breed Center in Jafar Abad Moghan, were used for analysis. The base population year was 1988. Analysis of the records was performed by ASReml software. INBREEDING depression was estimated as the regression of performance on the individual INBREEDING coefficients via fitting an animal model. The mean INBREEDING for all animals, females and males, were 0.500, 0.515 and 0.484 %, respectively. Totally, 24.22 % of all the animals were inbred. The mean of INBREEDING for inbreed animals was 2.062 %. The rate of increased INBREEDING per year for all animals was 0.05%. The INBREEDING depression for body weight traits at birth, 3, 6, 9 and 12 months of age was, respectively, -0.007, - 0.291, - 0.026, -0.018 and -0.041 kg, per 1% increase in individual coefficient.