Abstarct: As the operation depth of large-scale open-pit mines increases, the cost of production increases accordingly. Therefore, the need for reducing the costs drives design engineers to adopt less costly underground approaches. Among the underground methods, Block caving method can have the lowest operating cost for extraction of deep and large mass deposits. On the other hand, the high cost of block caving developments, engineers should be ensure that this method can be implemented before beginning of the project. Technically, the challenge of cavability, especially for high strength ore deposits, has always been addressed by designers. Many of the key variables of the block caving method such as undercut design draw point geometry draw column height and draw rate are a function of rock mass fragmentation. These variables play an important role in initiation of cavability, its continuation and crop production with appropriate fragmentation. So there are complex interactions between parameters. In this study, all the factors affecting the feasibility of this method have been explained. Rock engineering systems (RES) have been used as a power full approach for examining the interaction of these factors with each other by coding the interaction matrix of the rock engineering system, focusing on indirect influences of parameters. For reducing the uncertainty in ESQ coding of interaction matrix, the fuzzy system have been applied. Thereafter establishing the indirect interaction matrix is done, using structural analysis method PWP. Finally, after analyzing the improved interactions matrix, the indirect fuzzy index for workability of block caving method has been developed. For this purpose, 23 affecting factors on workability of block caving method are classified into four main groups of geomechanical, environmental, geometrical and operational factors baxsed on the results of previous studies. Finally, using Indirect Fuzzy Interaction Matrix, the workability index of the proposed block caving Method was calculated and its values fo ESQ r Diablo Regiment and Reserve Northe and kemess were calculated. In order to complete the study, the results were compared with the data obtained from the reports of the mines, indicating that the proposed method was well adapted to estimate the workability of the block caving method.