Commonly two methods including direct (core analysis) and indirect (evaluation of well logging data) used to determine lithology. These methods require a lot of time and cost. Therefore, for economic reasons, only cores of a few wells of a field are available, but well logging data are available for most wells. In this study, the seismic data of one of the Southwestern oil fields of Iran were used along with the available logs of wells of this field in order to use the extracted relationships between seismic attributes and values of the anhydrite volume in the wells to estimate the anhydrite volume in wells intervals using artificial neural networks method.