Abstract: The slope failure pattern recognition system regards rock mass structure as the basic controlling factor, and, considers the feature of rock mass, the shape of structural plane and the structural parameters of slope at the same time. The system organically combines between pattern recognition technique and expert system, and five lypes of rock mass slope are detemiined. It has advantages such as combining with project closely, obtaining the quantitative result, plain inference rule and convenient application. It proves the system's practicability and effectiveness that the result is in accord with the practical situation.