Higher density pulsed current,whic h is considered as an external transient energy and an environmental appl ying work poured into a melt during solidification,is used to refine solidificati on structures of 2024Al -alloy with t he higher melting tem-perature in the present paper.Experimental results show that the solidi fication structure can be remarkabl y refined by the appli-cation of the higher density pulsed c urrent.A primary refinement mechan ism is discussed in detail and some new questions to be solved are also pointed out.