Poly4-vinylphenol (P4VP)/multi-wall carbon nanotubes(MWNTs) multi-layer sensitive films were deposited on interdigitated electrodes by airbrush technology to detect toluene vapor at room temperature.The surface and section morphologies of the multi-layer films were observed by a scanning electron microscope(SEM).It is found that the resistance of the sensor increases when it is exposed to toluene vapor and the response has a good linearity with the concentration of toluene.The results show that the P4VP/MWNTs three-layer film sensors have better sensing properties compared with the two-layer film sensors.The related sensing mechanism is studied in detail. Poly-vinylphenol (P4VP) / multi-layer sensitive films were deposited on interdigitated electrodes by airbrush technology to detect toluene vapor at room temperature. The surface and section morphologies of the multi-layer films were observed by a scanning electron microscope (SEM) .It is found that the resistance of the sensor increases when it is exposed to toluene and the response has a good linearity with the concentration of toluene. The results show that the P4VP / MWNTs three-layer film sensors have better sensing properties compared with the two-layer film sensors. the related sensing mechanism is studied in detail.