In this article, the authors propose a stratigraphic slice interpretative visualization system, namely slice analyzer. It enables the domain experts, i.e., geologists and oil/gas exploration experts, to interactively interpret the slices with domain knowledge, which helps them get a better understanding of stratigraphic structures and the distribution of the geological materials, e.g., underground flow path (UFP), river delta, floodplain, slump fan, etc. In addition to some domain-specific slice edit manipulations, a sketch-based sub-region partitioning approach is further presented to help users divide the slice into individual sub-regions with homologous characteristics according to their domain knowledge. Consequently, the geological materials they are interested in can be extracted automatically and visualized by the proposed geological symbol definition algorithm. Feedback from domain experts suggests that the proposed system is capable of interpreting the stratigraphic slice, compared with their currently used tools.