Resistance tests were carried out against the brown rot fungus * 2Poria monticola*1 using test specimens of chir, against a soft-rot using chir and mango and against the termite <i>Microcerotermes beesoni</i> using mango. Acetylation with thioacetic acid at a weight percent gain (WPG) of 18% gave good resistance to the brown rot fungus. At a WPG of at least 8%, fairly good resistance to the termite was achieved, but there was no observable resistance to the soft rot at the WPGs used. -- AATA