The heat transfer coefficient on tooth faces must be known when calculating temperature rise on tooth faces. Though analytical fling-off cooling of gear teeth and experimental results about the adhesive amount of oil have been already reported, there have been few reports about heat transfer coefficients on tooth faces based on experiments and calculated from actual conditions. In this paper, the temperatures of the tooth faces and of the oil were measured, so the heat transfer coefficient was evaluated based on the temperature difference between the tooth face and the oil. The heat transfer coefficient concerning two conditions was evaluated analytically.