Abstract: To search after the quality changing law of Cortex Moutan from Chongqing so that we can confirm the best growing stage and harvesting time to guide production according to GAP. And to setting up a method controlling TCM quality .We setted up characteristic chemical ingredients fingerprint of Cotex Moutan from Chongqing. And gained the chemical ingredients chromatogram of the samples, analyzed the quality changing law during its growing progress by similarity calculating. The testing results showed that the chromatogram similarity degree of the samples which have grew for 4~5 years and harvested in Octobor is the highest with the chemical ingredients characteristic fingerprint of Cotex Moutan from Chongqing. It also showed the chemical ingredients chromatographic fingerprint is a technique, which can evaluate quality of traditional material medicine from various visual angles. It is more effective to guide the culture of herbs.