The invention discloses a solenoid-drive rotating fluid self-variable resistor for electronic or electric systems. The solenoid-drive rotating fluid self-variable resistor is characterized by mainly consisting of a containing cavity, a conducting fluid, a magnetic field, an electrode and a resistor body, wherein the conducting fluid is loaded in the containing cavity; the volume of the conducting fluid is smaller than the effective volume of the containing cavity; the resistor body is positioned at the center of the containing cavity and contacted with the conducting fluid; a part of the resistor body is exposed to the unoccupied cavity of the containing cavity; the electrode is positioned in the containing cavity and contacted with the conducting fluid; the electrode and the resistor body form an electric access through the conducting fluid; the magnetic field has a weight in the vertical direction of the liquid surface of the conducting fluid between the electrode and the resistor body. The solenoid-drive rotating fluid self-variable resistor for electronic or electric systems is simple in structure, difficult to damage, low in cost and durable.