A series of research results on the influence of soybean to the bioavai?lability of non-heme iron in diet are reported. It is proved that Soybean and some of its products decrease the bioavailability of non-heme iron in diet by human observation and animal experiments. This result is due to insufficient control over the inhibitors and utilization of the enhancers of the bioavailability of iron in soybean itself.Experiments show that through some special treatment processes such as sprouting, fermenting and making bean curd, the above disadvantages may be effectively reduced and remarkably increase the bioavailability of the non-heme iron. These conclusions possess both theoretical and practical meaning for full utilization of soybean protein and effective prevention of iron deficiency anemia.