The fretting fatigue test of austenitic stainless steels, JIS SUS304 and SUS316, was carried out in 0.12MPa hydrogen and air. The fretting fatigue strength of both materials was reduced by hydrogen. One of the possible causes was adhesion between the fretting surfaces which was predominant in hydrogen. The effect of specimen finishing on adhesion was also verified. For this purpose, two surface roughness were prepared with Ra = 0.420μm and 0.008μm. During the fretting fatigue test of these specimens in air, adhesion occurred in the smoother surface specimen but did not occur in the rougher surface specimen. As a result, the fretting fatigue strength decreased when adhesion occurred. Therefore, it can be considered that adhesion resulted in the reduction of the fretting fatigue strength in smoother specimens in air and in 0.12MPa hydrogen. Strain-induced martensite was found in the region of the adhered part, possibly due to the severe cyclic strain occurred locally at the adhered region.