Abstract: Based on the gradient theory，a gradient dependent nonlocal friction model was established and used to analyze bolt． By using Mindlin's solution of displacement，a solution of shear stress in the anchorage was derived． The nonlocal effect on the contact surface was revealed and the solution of shear stress of the anchorage section was given． The results were compared with those obtained by the gradient dependent nonlocal friction model and local frication model． Factors affecting the nonlocal friction were discussed． Taking account of the nonlocal friction effects， the shear stress peak value in the anchorage zone was smaller than the one without the consideration．