It was studied by us that new technologies using strong pulsed magnetic field and electric current were applied to refine metal's solidified structure.These technologies improved remarkably the solidified structure of LY12 aluminum alloy and made the solidified grains more equiaxed and apparently finer compared with that of the normal sample,which is of more dendrite grains.The stronger the strength of the pulsed electromagnetic field,the better the improvement effect was.The refinement mechanisms of the new technologies were analyzed theoretically.New phenomena and problems occurred in our experiments were also pointed out in this paper.