Abstract: In order to verify the validity of direct current potential drop(DCPD) inspection technique for inspecting the defects and its size in metallic foam, the real metallic foam inspection experiment by DCPD was conducted. Five specimens with defects of different sizes were fabricated. Direct current was loaded to the specimens respectively and the potentials on the middle line of the top surface of the specimens were measured. By making difference and filtering operation, the S/N ratio of the measured signals was improved. In addition, a numerical model was built to simulate the DCPD signals by using an FEM numerical code. Based on the experimental and the numerical results, it showed that the defect in the actual metallic foam could be detected by using DCPD technique, and the size of the defects depended on the amplitude of the potential signal, which laid a foundation for the quantitative NDT of the metallic foam.