The sulfurized layer was prepared on the surface of LZ50 steel by low temperature ion sulfuration technique.The rotational fretting wear tests of sulfurized layer were carried out under different angular displacement amplitudes in dry sliding and oil lubrication.The wear scars were analyzed by scanning electric microscope,energy dispersive spectroscopy and surface profilometer.The experimental results show that the sulfurized layer show different running condition fretting map in oil lubrication compared with drying sliding.The boundary between slip regime and partial slip regime moves to the left.The width of the slip regime is broadened.In the partial slip regime,the friction coefficient of the sulfurized layer in oil lubricating presents as a constant which is significantly lower than in dry sliding.And the damage of the sulfurized layer is very slight.In the slip regime,the friction coefficient of the sulfurized layer in oil lubrication exhibits ‘initialascendantsteady stages’,which is still lower than that in dry sliding.Moreover,the wear mechanism of the sulfurized layer in oil lubrication is mainly abrasive wear and delamination in the slip regime.