The work aims to provide basis for renovating “red wall” by studying composition, structure, color of red wall (also called “palace wall red”) at the Beijing ancient palace and temple buildings. Color data was collected at the Forbidden City, Imperial Divine Temple and Temple of Agriculture. Samples were analyzed by using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffractionmeter. The color of “Red Wall” differed a lot at different buildings and in different locations in the same building. The lime consisted of was CaCO3, the red lime consisted of CaCO3 and Fe2O3, the red slurry consisted of Fe2O3, CaCO3, CaSO4?2H2O, rice juice (traditional technique) or organic polymer (modern technique). Since color of the “Red Wall” differs a lot in different locations at the Beijing ancient palace and temple buildings, white lime doped with iron oxide red is recommended to make up and plaster the “Red Wall”, and coating formulation adopting modern technique is recommended for the external fa?ade during renovation.