The decay resistnaee of the rubber wood treatedo with preservative TWP by full-cell process was tested after 2～9 months airseasoning. The resuits showed that the board with 4～6cm in thickness was fully penetrated by TWP with a loading of BAE (Boric Acid Equivalent) over 0.2% (w/w) in the outer part with a thickness of 15mm. The durability of the treated wood was raised to durable grade, but the decay resistance was relative poor in field. The effect of different penetration depth on decay resistance of treated board was also studied.