Abstract: Industrial research for improving the solidification structures of billets with the Electric Pulse Modification (EPM) technology was carried out in Anshan Iron and Steel Group Company. The experimental steel is 09CuPCrNi. The billet size is 150 mm×150 mm. Experimental results show that the solidification structure of the billet was fined obviously by applying electric pulse on the molten steel in tundish. The length of columnar dendrite and the space of primary dendrite of the billet with EPM treatment is much smaller than that of the untreated billet. The zone of the equiaxed grain in the center of the billet is increased. The central shrinkage cavity was eliminated. The mechanical properties of the finished product satisfy the technical standards.