By consulting ancient herbal medicines and medical books， combined with modern documents and field investigations， the textual research of Pheretima has been conducted to verify the name， origin， producing area， quality， harvesting and processing changes， and sort out the relationship of origin between ancient and modern times， so as to provide reference and basis for the development and utilization of the related famous classical formulas. Through textual research， it is known that there are many aliases for Pheretima， the rectification of name was "Qiuyin" or "Baijing Qiuyin" in materia medica books. In the Song dynasty and later prescription books， the prescription name is mostly Dilong. From the beginning of

Yaowu Chuchanbian

（《药物出产辨》）， Dilong was used as the rectification of name. It is widely distributed in our country， which is produced all over the country and mostly wild. According to ancient Pheretima with "Baijing Dilong"， "Jingbai Shenzi" and "Datiao" as the principles of medicine， combined with historical origin， producing area and easy access， it is confirmed that Pheretima used in ancient times to the present is mainly

Pheretima aspergillum

， and it also has many other Qiuyin as Pheretima for medicinal purposes.

Chinese Pharmacopoeia

has unified the origin of the Pheretima since the 1995 edition based on historical origins and actual harvesting conditions. The medicinal material processed by

P. aspergillum

was called Guangdilong， and the medicinal materials processed by

P. vulgaris

，

P. guillelmi

and

P. pectinifera

were called Hudilong. Since then， all the herbal books published in the future are in line with

Chinese Pharmacopoeia

that was implemented at that time. The authentic production areas of Guangdilong are Guangdong and Guangxi， and the authentic production areas of Hudilong is Jiangsu， Shanghai， Zhejiang and Anhui. The Guangdilong produced in Guangdong and Guangxi has the best quality. After harvesting， remove the soil and offal， wash and dry. Clinically cut into sections for medicine， or prepare medicine according to prescription. The Pheretima in ancient used "Baijing Dilong"， "Jingbai Shenzi" and "Datiao" as the mainstream quality evaluation standards. According to historical origins，

P. aspergillum

should be the main source of Pheretima， and its quality is better than other species. Therefore， it is recommended that Pheretima in Shentong Zhuyutang use

P. aspergillum

， which is produced in Guangdong， Guangxi and other places. After harvest， the abdomen was opened in time to remove the viscera and sediment， washed and dried.