Abstract: The porous polyimide/ mesoporous silica nanotubes (PI/MSNT) composite films were fabricated by using polystyrene microspheres (PS) as the pore-forming template while MSNT as the additive, whose porous structure and morphology were subsequently characterized by various techniques. On this basis, the liquid paraffin oil was infused into the porous structure of composite films via a vacuum wet impregnation method to prepare oil-containing PI/MSNT composite films. The addition effects of MSNT on thermal stability, oil-storage capacity, mechanical and tribological properties of porous PI/MSNT composite films were investigated in detail, and the results demonstrate that these properties of porous PI were apparently improved upon the addition of MSNT. Specially, the tribological properties of the oil-containing PI/MSNT composite films were better than those of the single-component oil-containing PI film, demonstrating the composite film was more suitable for high-load friction conditions.