Influenced by the climate change and the extreme weather, debris flow has become a common disaster in Taiwan in recent years. To protect people from the impacts of debris flows, monitoring and warning system were established in Taiwan since 2002. Most of the warning systems or models are based on the analysis of rainfall, the major cause of debris flow (Jan et al., 2003; Jan and Lee, 2004; Lee 2006). The measurement of rainfall, however, is an indirect option of debris flow monitoring (Huang et al., 2013), resulting in "false alarms" most of the time. One direct measure is to use geophone and broadband seismograph (Chu et al., 2014; Huang et al., 2012) to record the vibration signals of debris flows. This study analyzed the vibration signals of a site in Shenmu, Taiwan, where debris flows frequently occurred (Lee et al., 2014), and discussed the performance of using vibration signals for debris flow warning. The results of using vibration signals were practically promising for debris flow monitoring.