The combination of ammonium polyphosphate（APP） and silica gel is considered to be efficient flame retardant and smoke suppresser for wooden materials due to their excellent adsorption and catalysis properties. APP/silica gel could be absorbed by 202% in mass in paulowna when using vacuum pressure impregnation followed with vacuum drying. The wood so prepared were not able to be burned during CONE test, and did not show obvious combustion even burned at 760 ℃. The total heat release for treated paulownia wood was slightly higher than that treated by APP solely. However, the total smoke production and CO yield of treated paulownia wood were significantly reduced. The results indicate that, combination of APP and silica gel in paulownia wood not only contributed to excellent flame retardance, but also to inhibition and conversion of smoke in fire.