This paper describes the effect of tool surface integrity and lubrication mechanism on micro cutting. In this study, two kinds of tools with different surface integrity were applied to investigate tribological phenomena in micro cutting process. Orthogonal cutting test was conducted and cutting force was measured by changing the cutting conditions. Cutting conditions were air, nitrogen and lubricated condition by paraffmic oil. As a result, it is found that the difference of surface integrity affects lubricants penetration into the interface between tool and chip. Cutting condition, particularly oxygen concentration, affects friction. Cutting force was stable and adhesion on tool rake face was prevented on dry condition.