The implantation of bone matrix in muscle bag or trepanation defects of rats with greatest reproducibility will induce osteogenesis and defect healing. The phenomenon of osteo-induction was possible to obtain only in first steps in higher developed mammals. Investigations in nude rats have shown a clear difference in biologic reaction on the matrix of various species. The osteo-regeneration in replacement weak defect of ulnar bone in dogs showed a massive greater reactivity of autogenous spongiosa, whereas bank spongiosa and bone matrix produced not more new bone as the control. An increase of osteoinductive matrix potency is a supposition for practical use in case of severe bone defects.