The design of a jointed rock slope angle is an important problem in the design method of rock engineering. The prediction of displacements and deformations of rock slope is an important problem of the rock mechanics in the design of rock slope angle. UDEC analyzing model software is the powerful tool for investigating the slope failure mechanism and predicting the slope sliding. Hence this program was used to investigate the potential for slope scale structurally controlled instability in the west wall of Takht-E-Gonbad open pit mine. The two-Dimension Discrete Element Analysis shows that some of walls are stable and by the changes of the walls orientation the other will be more stable.