Under tension and shear conditions related to unloading of rock mass,a linear elastic fracture mechanics model of jointed rock mass is established. According to the model, the equations of stresses, strains and displacements of the region influenced by the crack but relatively far away the crack(the distance between the research point and the center of the crack is longer than the length of crack) are derived. They are important for evaluating the deformation of cracked rock. It is demonstrated by the comparison between computational results of these theoretical equations and the observed data from unloading test that this model are applicable for actual engineering.