Abstract:The gum-producing life of rudder tree (Hevea bresiliensis (Hbk.) Muell. -Arg. ) is 25-30 years. In China, about 800,000m3 rubber wood will be produced each year and needed to be treated by preservatives to ensure wood products free from biodegradation. Although the complex of boron phenol has been used for long time, it contains Na-pcp which is very poisonous to human being and has been banned by some countries, A new wood preservative TWP which is a complex of three water soluble preservatives was developed at the Research Institute of Tropical Forestry,CAF with the advantages of high effec tiveness, broad spectrum, long lasting action and low toxicity to human. Results from the laboratory toxic tests of TWP showed that 1) in controlling decay fungus (Coriolus versicolor (L. ex Fr.) Quel) the threshold retention is at 2.2-3.2kg/m3, 2) in controlling bostrychid powder-post beetle(Heterobostrychus aeqalis(Waterhouse)) the retention of killing egg-laying and larval is at 1.0kg /m3, 3) in controlling bluestain fungus (Botryodiplodia theobromae Pat.) and mixed mould fungi, the inhibition concentration is at 1.0% and 1.5-2.0% respectively, and 4) TWP is safe in use to human, animals and environment. On acute male mouse LD(50) of TWP is at 1, 301 mg/kg. Application trials of TWP were carried out in four wood factories in 1988-1990. The rubber green sawn can be successfully treated by full-cell or oscillating pressure processes with 2.0-2.5% TWP, Average net retention of TWP is at 4-+0.7kg/m3. The preservation effect of the TWP is better than emulsion of MBT and TCMTB at concentration of 2.0%. It is considered that TWP is a rubber wood preservative of low toxicity and may be instead of the complex of boron phenol.