From the fresh roots of Trichosanthes kirilowii Maxim. var. japonicum Kitam., the following substances were identified: methyl palmitate, palmitic acid, suberic acid, alpha-spinasterol, stigmast-7-en-3 beta-ol, alpha-spinasterol 3-O-beta-D-glucopyranoside, stigmast-7-en-3 beta-ol 3-O-beta-D-glucopyranoside, bryonolic acid, cucurbitacin B, cucurbitacin D, vomifoliol, ethyl alpha-L-arabinofranoside and D-glucose. The bitter taste of Trichosanthes Root was considered to be due to cucurbitacin B and D.