It's important for TCM professionals to understand and apply TCM classics,and thus to improve their treatment and diagnosis.In the clinical treatment of senile melanosis coli,the famous practitioner in Qing Dynasty,Chen Shiduo's thought “ascending and descending depending on each other & descending through ascending (Sheng Jiang Xiang Yi,Yi Sheng Wei Jiang)” was applied,which enhanced the pattern differentiation and treatment of common symptoms of constipation.