Abstract: In order to approach the possibility of obtaining an austenitic-bainitic ductile iron weld under continuous and rapidly oooling condition of welding, the effects of Ni, Mo、Ni-Mo and Ni-Mo-Cu alloy system on the as-welded microstructure have been studied. The composition range of alloy elements is given for getting an as-welded microstructure of austenitic-bainitic ductile iron. The research furnishes a basis for developing new welding material.