Effects of joint width (JW) on the macroscopic stress-strain curve, the failure process and mode of jointed rock specimen (JRS) in plane strain compression are modeled by use of FLAC. The failure criterion of intact rock outside the inclined joint is a composite Mohr-Coulomb criterion with tension cut-off and the linear strain-softening post-peak constitutive relation is adopted. The joint is treated as quadrate elements of ideal plastic material beyond the peak strength. A written FISH function is used to automatically find elements in the joint. Numerical results show that the peak strength of JRS depends on JW and is lower than that of intact rock specimen without joint. For JRS, the shear strains are concentrated into the joint or the new generated shear bands (NGSBs); the peak strength decreases with an increase of JW. At lower or higher joint inclination angle (JIA), the failure mode and pattern of NGSBs are not related to JW. The post-peak response becomes ductile at wider JW and higher JIA. The post-peak slope of stress-strain curve at lower JIA is not dependent on JW since the width and inclination angle of NGSBs are not affected by JW.