Abstract: The typical conventional CT system employs the digital integrating sensor. It is difficult to identify X-ray attenuation characteristics for different materials. This paper focuses on color CT imaging technique based on MARS X-ray spectral CT system to analyze different materials. In experimental study, we scan the rubber tube corroded by iodine solution and a mouse injected with a contrast agent (Gold Nanoparticles (GNP)) in different energy ranges, and extract and quantify X-ray energy spectrum information to reconstructed color projection images of the rubber tube and color CT image of the mouse chest. The picturesdemonstrate the complex structure of the rubber tube and concentration information of the gold particles in the mouse chest. X-ray spectral CT could represent more richer structure information and different composition of materials.