Recently, there are many prominent problems about the quality ofIndigo Naturalis. To explore the underlying reasons, both ancient and modern herbal literatures were reviewed. Through the organization of recordings onIndigo Naturalis, the traditional process method required soaking and fermentation, stiring and depositing, foaming and shade drying. The currently usedIndigo Naturalis was mostly isolated and purified from crude deposit -“Cu-Dian.” The modern process technique ofIndigo Naturalis was gradually deviated from the traditional processing method. This paper also discussed the quality standards ofIndigo Naturalis. The author considered that the current standard on descriptions ofIndigo Naturalis characteristics was deviated from the traditional morphological features ofIndigo Naturalis, which should be further researched and verified. Therefore, this study provided certain references for the quality control and market supervision ofIndigo Naturalis.