The modification of liquid metal by electric pulse (EP) is a novel method for grain refinement. In this study, based on the reported structural heredity of EP-modified liquid aluminum, the structure tests of EP-modified liquid aluminum were conducted by using high temperature X-ray diffractometer. The results show that the EP-modified liquid structure also tends to be slack and unordered with increasing temperature, which is similar to that of the unmodified. However, the quantitative characterization denoted by the liquid structure parameters exhibits their discrepancy. At the modifying temperature of 750°C, the order degree of EP-modified liquid aluminum is remarkably strengthened and the value of average atomic number per cluster changes from 119 (no EP) up to 174 (EP) by an increase of 46%. These tests experimentally testified Wang’s electric pulse modification (EPM) model that was built only by phenomenology and hereby the mechanism of grain refinement resulting from EPM is further elucidated.