Abstract: Investigation of Alloy-800 under the column-against-column contact with various normal loads of 80 N and 50 N and displacement amplitudes from 2 μm to 40μm in ambient environment is demonstrated in this paper. Experimental results show that the fretting regime of Alloy-800 is transformed from the partial slip regime into the mixed fretting regime and gross slip regime by its fretting behavior with increaseing displacement amplitude under the same normal load. The coefficient of friction in the partial slip regime is lower than that in the mixed fretting regime and gross slip regime .Three different fretting regimes can be observed under fretting condition. In partial slip regime, micro-slipping occurs at the edge of the contact with slight damage and small crack, the wear scar area and fretting wear volume in gross slip regime are large, and in mixed fretting regime, aggregation of debris is obvious. Abrasive wear and friction oxidation are main fretting wear mechanisms of Alloy-800.