Urushi-shitaji, a ground for applying iiriishi (Oriental lacquer), is made by mixing clay (jino-ko) or bole (tono-ko) with water and further by adding an equal amount of raw urushi. This paper describes the results of researches on Japanese urushi-shitaji. In the Jomon Period earlier than ca. 3rd century BC something similar to urushi was used on objects made by weaving bamboo. That method was no longer used in the later Yayoi period (3rd C.B.C. about 3rd C.A.D. ). The urushi-shitaji was brought into Japan along with Buddhism. Urushi-shitaji seen on coffins and urushi kawa-bako (boxes made of untanned leather) in the 7th and 8th centuries was a special kind of iirushi-shitaji, being dark brown, semitransparent and hard. Twelfth century urushi-shitaji represented by Konjiki-do of the Chusonji Temple uses bole, not clay. Thirteenth century Chinese urushi-shitaji is quite different from Japanese ones and there is a great possibility that it was made of ashes of deer antlers and urushi. -- AATA