Heartwood of various commercial timbers, wooden board materials, thermal insulating materials and fire-protection materials were tested for their resistance against Coptotermes formosanus. Specimens, measuring 2×2×2cm, were put on a laboratory colony of C.formosanus together with akamatsu (Pinus densiflora) sapwood blocks as controls. After 1 month the specimens were recovered, and mass losses caused by termite attacks were measured. Termite resistance of the materials was graded by the mass loss and the visual inspection.
Japanese three domestic species (hinoki (C. obtusa endlicher), hiba (Thujopsis dolabrata), sugi (Cryptomeria japonica)), cypress pine (C. macrocarpa), Alaska-ceder (C. nootkatensis), kapur (Dryobalanops spp.), and mahogany (S. macrophylla) were graded as "high resistant". Mass losses of the blocks of Siberian red pine (Pinus syluestris) and gmelina (G. arbolea) highly varied within the species. Plywoods made by tropical species, inorganic board materials and radiata pine MDF showed high resistance against C. formosanus. Other board materials, most of commercial soft wood plywoods, and OSB were graded as "low resistant". Common thermal insulating foams were severely attacked by C. formosanus. In fire-protection materials, expanded concrete was high resistant against C. formosanus, but plaster board was sensitive.
Relationship between mass loss of all materials tested by termite (C.formosanus) and dry-based density showed a negative correlation under 5% risk. The density of building materials is estimated a primary check point for termite resistance.

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