Abstract:A variety of simulative experiments on the discoloration behavior of catalpol, paulownin and sesamin separated from methanolwater extractive of Paulownia wood (Paulownia elongata S.Y.Hu) were conducted under different conditions. The results indicate that the color change of catalpol is mainly affected by acidity, while the discoloration of paulownin and sesamin are caused by both radiation and oxygen. The variation of temperature and humidity also have effects on the discoloring of catalpol. The color change of Paulownia wood is a result of a combination of all the factors. A tentative mechanisms of discoloring reaction were figued out.