Abstract:In this study, main noise resource in CAB of the caterpillar skidding tractor 50 were identified by "elimination" and "spectrum analysis". According to analysed results, the multiple input/single output models with ear-side noise for output and other noise resources for input were respectively set up, programmed and calcutated by a computer to Solve the influence degrees of various noise resurces inputted on driver‘s ear-side noise. Some measures for reducing main resources were adopted, so that the value of driver‘s ear-side noise is decreased by 5.5dB(A). The restults can provide effective means for reducing the noise in the CAB.