Abstract: In this research, rotational bending welded joint fatigue specimen was used. The welded joints of the specimen in the same state of the initial microstructure and residual stress were subjected to different strength of the shock wave by changing the distance between the explosive and the specimen. The results indicated that after the explosion treatment, the fatigue property of the plastic, clastic and elasto-plastic zones on the 16MnR steel weld, attected by the explosion shock wave, arc all improved but the three zones have different characteristics.