Abstract:Lumbers (poplar, pine etc.) beated with chemical modifying agenb(LM) possess a Mgh andshdnk efficiency (ASE) at 20 to 30 chemical weight percent gains (WPG). The modified wood has broad nnge efficiency against mold, termite, sapstdn and decay fungi. It shows a high degree of fire re.dancy. Wood beated with chemical modifying agents (LM) has been proved through examinadons that itt s toxicity LD50 is more than 10000mg / kg; so it cause no harmful effect to people and domestic animals.