Zhao Yongxian’s mansion, an important Ming Dynasty monument in Jiangsu province, was decorated with colored paintings applied to unplastered wooden surfaces. In order to protect the colored paintings, analysis was conducted to characterize both the pigment composition and the layer structure, using XRD, FTIR, EDS and visible microscopy. Based on the results of these experiments, many conservation problems were solved. These problems included the presence of oil-based substrates in the aged wood that could easily be extracted out by the solvent; parts of paintings had been covered by plaster, removal of the coating, etc. Natural materials similar to the original adhesive were used to reinforce the pigment; the pigment was sealed in using a silicone solution. This treatment not only effectively lengthened the life of the reinforcement material, but also conformed to the re-handling principles.