[Introduction] Clarifying the nature of polarity for electro acupuncture, document retrieval and discussion was conducted on electric corrosion.[Materials and Methods] "Energization Current on Acupuncture Needle", "Direct current"and "Electrolytic Corrosion" were used for Key Words searching citation in Medical Journal Web, Google Scholar, PubMed, and Elsevier.[Results] Information retrieval resulted in one article Nine Japanese articles were selected excluding those are not related acupuncture and overlapped content with other. The results of nine studies used saline solution. Two studies were examined using the piece of chicken or pork meat. Two were animal research. Three used human subjects. Six Foreign articles were selected. [Discussion] All the reports indicated that the needle applied positive polarity current did not show electrolytic corrosion so far as not conducting excessive huge current directly from such as car battery. Although, it was shown that no noticeable electrolytic corrosion was elicited on the surface of needles that were the negative polarity even when an excessive current was applied.[Conclusion] It is the Positive needle electrode that elutes metal. Positive electrode should be a skin surface indifferent electrode as case of applying direct current using the acupuncture needle on the human body. Acupuncture needles made of stainless steel wire material SUS316 are supposed or strongly suggested more suitable for energizing than other stainless steel wire materials.