It is examined that the effects of water vapor as green coolant and lubricant on the cutting of austenitic stainless steel. Compared to nitrogen, oxygen, argon and carbon dioxide gas applied and dry cutting, water vapor produced the lowest cutting force and deformation coefficients, improved the machined surface appearance and helped to chip forming and breaking. And the lubricating actions of water vapor and gases may have the relation with the molecule polarity and the capacity of adsorption in the cutting zone. All these gases and water vapor have the green characteristic without pollutions. Comparably, water vapor may be a good selection for the green machining of austenitic stainless steel.