This paper reports studies of the corrosions,fatigues,and fracture characteristicsof cobalt-base cladded coating on 2Cr13 steel substrates,performed at 50 Hz in 3.5% NaClsolution(PH=7).The corrosion fatigue lifetime curve was determined. The results showthat almost all corrosion fatigue cracks of laser cladded specimens derive from pits on thesurface of 2Cr13 steel substrates. Cobalt-base laser cladding coatings on the specimens gavea greatly increased corrosion fatigue lifetime comPared with 2Cr13 steel specimens becuase the initiation of corrosion fatigue cracks is restrained by the laser cladded coating. From the results, t may open up a new way to the application of laser cladding technology.