Abstract: It was studied in this paper that the effects of aqueous alkali on the penetration and the color of paulownia wood after soaking in NaOH aqueous solution.It was also investigated the promoting effects of this solution on wood bleaching.The result showed that NaOH could increase wood penetration and bleaching effect without damage to wood color.After soaking in 0.3% NaOH aqueous solution for 2 days, the samples were treated in 2% Na 2S 2O 4 for 3 days.Half a year later the lightness and whiteness of these samples were obviously higher than the untreated samples, and the chromatism was lower than that of the untreated samples.

Key words: NaOH pretreatment, paulownia wood, bleaching