Abstract: In this paper,theoretical and experimental studies on the optimization of the interference fit of a bolt joint have been made.The analytical solution to the elastoplastic stresses and strains in a sheet with an unloaded interference-fit bolt was discussed at the first. On the basis of the discussion of the stresses distribution around the hole, a criterion of optimized interference was proposed.A series of fatigue tests were conducted finally to give recommended parameters for this type of joint.