The study of population structure by pedigree analysis is useful to identify important causes that affect the genetic diversity of populations. In this research, the genetic diversity and population structure were studied in the Kermani sheep breed based on pedigree information of animals registered in the Shahrbabak sheep breeding station. The mean generation interval, mean inbreeding, mean coancestry, mean relationship, effective population size and probability of gene origin parameters were estimated. For this population, the mean generation interval and the effective population size were 4.5 years and 284 head, respectively. The effective population size was found using the individual inbreeding increases. The mean coancestry, mean relationship and mean inbreeding were estimated 0.35, 0.69 and 0.09 percent, respectively. The total number of founder animals, the effective number of founders, effective number of ancestors, effective number of founder genomes (founder genome equivalents) and effective number of non-founder genomes, were estimated 406, 209, 73, 144, 454 heads, respectively. Approximately, 50 percent of genetic diversity of population was explained by the 26 ancestors. The results of this study indicated contribution of the founders and major ancestors to the population has been unbalanced due to the selection of animals and the genetic variability of the population decreased compared to the founder population.