The surface temperature of gear teeth is one of the important factors for evaluating the scoring resistance of a gear. In a present paper, the comparison of numerically calculated value with experimentally measured value is reported. The calculation of surface temperature was performed with the following procedure. First, the dynamic loads applied to gear teeth were calculated in consideration of the variation of different factors, for instance transmission errors of test gears and total stiffness of gear teeth. Second, under the condition that there must be no temperature discontinuity over the contact zone of sliding surfaces, the temperature distribution over the contact area was calculated. On the other hand, the measurement of surface temperature was performed using the meshing gears themselves as a dynamic thermocouple. The results of numerical solution by means of a digital computer are in fairly good coincidence with the experimental results.