Abstract: In medical guide wire (1A), a tapered second helical spring (7) is interposed continuously between a first helical spring (6) and the third helical spring (8) each wound around a leading end portion (2). From a middle portion of the second helical spring (7) to a leading top end of the first helical spring (6), a spiral blood stream path (10) is serially provided along a line gap (C1) of the helical springs (7, 6). A gap-stopper (12) is provided between the leading end portion (2) and the second helical spring (7) in order to induce a high speed spiral blood flow (17) along the spiral blood stream path (10) when the leading end portion (2) reaches a diseased area (13). The high speed spiral blood flow (17) provides the leading end portion (2) with the advancing force (F) and the rotational force (T).