Abstract: The motion and friction of soil particles and the crack expansion in land will generate infrasound waves just before landslide.In order to analyze the characteristics of infrasound signals just before landslide,six groups of landslide simulation experiments are conducted with a soil slope model,and the generated infrasound signals in the experiments are acquired.The time-frequency characteristics of the signals are analyzed by using the short time Fourier transform and the energy features of the signals in each frequency band are studied by wavelet decomposition in this paper.The result shows that there are special infrasound signals generated before landslide,and the frequencies of the signals are mainly concentrated in 0.5~6 Hz and 12.5 Hz around.According to the development law of land slide creeping stage,the infrasound signals of 0.5~6 Hz are generated by the intermittent motion and friction of soil particles on the slip surface;and,the infrasound signal near 12.5 Hz is generated by the crack expansion of the sliding body.The infrasound characteristics obtained by the experiments can be used as an important reference for the infrasound monitoring of landslide.