Abstract：According to fractural condition and infilling material condition and based on theoretical mechanics,the paper studied the reflection and transmission of wavelet from fault plane. The used wavelet is approximation of dominant wavelet frequency in time domain. It is considered by analysis that the fault plane reflection relies on the mechanical attributes of infilling materials and is characteristics of band-pass filter when infilling materials are fluids. The transmitted coefficient contains the information of the filter and evaluation of wave impedance of fluids in broken zone of fault can be measured by decreasing ratio of dominant frequency of transmitted wave，thus the ratio between dominant frequencies of transmitted wave and incident wave can act as studying hydrocarbon-bearing indicative parameter of fault and further be used for detection of fault screen.
