Abstract: In the paper discussed is a big revision to the classic method the computation of the inbreeding coefficient. In particular, we shall give a pie-cewise iteration algorithm for regular pedigrees. By means of this algorthm we can greatly raise the calculativc speed of the inbreeding coefficient.For a grand pedigrees with primary breeders, we have found a breakdown algorithm, thereby it is very easy to find path chains.

Key words: Inbreeding coefficient, Piecewise iteration algorithm, Breakdown algorithm