The paper proposed a novel ultra-wideband matching load of substrate integrated waveguide (SIW). The proposed structure is implemented via mature printed circuit board techniques, while resistive film is employed to consume undesired electromagnetic energies traveling through the structure. Benefits from the planar structure, the matching load are easy for fabricate and have a low cost behavior, it is also good at integration with other planar circuits and have a relatively compact size, which is valuable for miniaturized high density microwave circuits. Electromagnetic simulations are employed to analyze and optimize the shape and dimensions of the structure, while the simulation results shown that the proposed structure has a good RF performance among the whole X band. Return losses of the matching load is better than 18 dB from 8 GHz to 12 GHz, while the whole dimension is not greater than 18 mm ×5.5 mm × 0.7 mm, realized on a four layer stack PCB.