Abstract: We have calculated marginal utility of breeding target characters of Inner Mongolian Aohan Merino Sheep with ＂difference method＂ acoording to breeding technique parameter,nutriology parameter as well as product and market parameter under breeding and production conditions at prese.We heve obtianed the results that the relative economic importance proportion is about 7：2：1 by standard calculating marginal utility of every target characters. This proportion is about 10：5：1 in adult ewe and about 5：2：1 in improved sheep if acoording to each kinds of sheep to be separately selected and separately treated.