Abstract: An impedance matching transformer for high-frequency transmission line includes a carrier plate, a plurality of conductive posts, a magnetic core and a microstrip inductor. During high frequency transmission, the impedance matching transformer is used as a balanced-to-unbalanced transformation between high-frequency transmission lines. The microstrip inductor includes a plurality of laminated non-conductive substrates, a plurality of conductive tracks laid on the laminated non-conductive substrates respectively. Each of the conductive tracks is electrically connected through vias. Finally, several outlet paths are led out, and then connected to conductively accessing holes.