Abstract: It was once a prerequisite for inbreeding coefficient calculation to find the number of pathway circuits. And it was very complicated and liable to errors in the calculation of inbreeding coefficients of multi-generation breeding individuals-Manual reference tends to have slips or doubles while computer reference, though accurate, needs a very long time-In order to simplify procedures and increase the speed and accuracy of calculation, found in practice was this method of inbreeding coefficient calculation using the following multi-generation equation-(K-N Nwhere.Ft-the inbreeding coefficient of the breeding individual of the presentgeneration,Fi,t-1- the average inbreeding coefficient of the last generation. Fi, t-2- the average inbreeding coefficient of the last but one generation. K- the number of inbreeding type combinations among M parents.N-the number of inbreeding types that may be expressed by "half" in the present generation.K- N- the number of inbreeding types that may be expressed by"full" in the present generation. satisfactory conditions, this method can calculate quickly and accurately the inbreeding coefficient of the multi-generation breeding individual without reference to the number of pathway circuits. And it was successfully used in the calculation of layer breeding programs. Its efficiency is 60 times higher than manual reference. This method, simple and suitable for manual calculation, produces satisfactory results, and hence, has a value of application.However, this iterative equation is limited in certain inbreeding coefficient calculations, which needs further study in the future,

Key words: inbreeding coefficient of domestic animals and fowls, iterative method, programming