Nodularizing treatment is a key operation in the production of ductile iron castings of predetermined microstructure and mechanical properties. The suitability of cored wire nodularizing method was investigated. The main factors for influencing magnesium recovery and nodularizing effect were discussed. The wide variety of nodularizing methods make difficult the selection of an optimal method for a given foundry. The comparison was made of both advantages and disadvantages among nodularizing methods commonly used. Finally, the selection rules of nodularizing methods were put forward based on the type of melting furnace, casting weight, magnesium recovery, productivity, temperature loss, safety and environmental impact. The present state, research progress, application situation and developing trend of nodularizing using cored wire in domestic and foreign in 40 years were overviewed by brief introduction of several examples. The future development of nodularizing ttreatment is revealed with higher quality, environment friendliness, automation and consistency.