In this study, we evaluated the age-induced degradation of wood structural components of the Changchun Palace in the Forbidden City. The wooden structural component (stand column) samples were taken from the interior of the main shrine (C1) and the exterior of the shrine on the south side (C2). Because of the location of C2 in an area where it has long been exposed to natural environmental conditions such as ultraviolet rays in sunlight, it could be seen to be severely degraded by visual evaluation. The columns were determined to have been made of larch wood (Larix gmelinii (Rupr.) Kuzen.). A variety of scientific methods, including X-ray diffraction (XRD), derivative thermogravimetry (DTG) and infrared spectroscopy (IR) were used for further analyses. The results show that the cellulose, lignin and hemicellulose of both C1 and C2 samples have degraded over the years, but the degree of degradation of the cellulose of C2 is more remarkable than that of C1, due to the long-term exposure to ultraviolet light in sunlight. DTG analysis also shows the hemicellulose in C2 had similarly degraded, with the result that the relative crystallinity of C2 is much lower than that of the larch wood used inside the shrine. Furthermore, analyses of chemical group changes by IR spectroscopy show that absorption peaks of C1 and C2 samples have weakened or disappeared at 1 732 cm-1, 1 635 cm-1, 1 510 cm-1 and 1 460 cm-1, indicating that chemical compositions of these larch wood samples have changed markedly, especially for C2. It is also noted that the absorption peak of C2 at the wave number of 1510 cm-1 which represents skeleton vibration of benzene ring originating mainly from lignin has disappeared. This suggests that photodegradation (degradation of lignin primarily due to irradiation of ultraviolet light) would be the main reason for the aging of C2.