One of the characteristics in Japanese charcoal-making is the so-called “ref ining”-a high tempera-ture treatment after the carbonization has almost finished. The writers made a study on the relationship between the properties of several kinds of Japa-nese charcoal and different intensities of ref in-ing. The study revealed that in the case of white charcoal the refining has proceeded sa.f fi-ciently and homogeneously, while in the case of black charcoal it was insufficient and partial. The study also revealed their physical and chemical properties as follows: