In this study, we performed the meshing teeth temperature survey experiments for the plastic crossed helical gears to examine the meshing teeth temperature estimation method which changed material of mating metal gear, production method and gear dimensions. From the result of the experiments, we obtain the following results; (1) Even if the material of the mating metal gear, manufacturing method and gear dimensions are changed, the mean flash temperature can be used as an index for estimating the increase in meshing teeth temperature. (2) If the material of the mating metal gear and the manufacturing method are the same, regardless of the operating conditions and the gear dimensions, the meshing teeth temperature can be estimated using the same equation from the mean flash temperature. (3) In the case where the material and manufacturing method of the mating metal gear are changed, the value of the slope of the relational expression between the mean flash temperature and the increase in meshing teeth temperature may change. This is thought to be due to a change in friction coefficient due to a difference in surface texture.