The failure precursor, acoustic emission and final failure mode are modeled using FLAC for heterogeneous rock specimen with initially random material imperfections in uniaxial plane strain compression. Beyond the failure of the imperfection, which is weaker than the intact rock, it undergoes ideal plastic behavior, while intact rock exhibits linear strain-softening behavior and then ideal plastic behavior once failure occurs. Shear band patterns depend on the distribution of initially random imperfections within the specimen. Although multiple shear bands can be formed when strain-softening behavior just occurs, the final shear fractures intersect the specimen only through a few shear bands. The shear band inclination approximately approaches a constant in residual deformational stage, which falls into the range of Arthur solution (the lower bound) and Coulomb solution (the upper bound). The specimen with fewer material imperfections exhibits more apparent acoustic emission in the vicinity of peak stress and in strain-softening stage.