In recent years, the volcanic reservoir has become a new focus in reservoir prediction. Generally, fractures constitute an important factor of the volcanic reservoir, and volcanic rocks are characterized by  variation of spatial distribution and complex internal lithology. Therefore, the detection of fractures in volcanic rocks is considered to be an research challenge. Based on the theory of prestack elastic impendence inversion and azimuthal anisotropy, this paper presents an idea for predicting fractures in the volcanic reservoir with prestack seismic data. First, the prestack elastic impendence inversion, as a highresolution inversion method, is introduced to predict the volcanic reservoir; then the change of kinetic property of seismic wave caused by fractures is analyzed, and the density and direction of fracture are predicted with the azimuthal anisotropy; finally, the distribution of volcanic reservoir as well as fractures is estimated comprehensively. The key to this idea is "detecting fractures with the thought of finding volcanic reservoir", and the special advantage of the method lies in its high resolution and outstanding prediction accuracy. As an example, this idea was used for reservoir prediction in a test area, with a satisfactory result obtained.