This part comments the part related to filiform needle(小鍼) among the contents of Ku Chim Sip I Won(九鍼十二原) in Young Chu(靈樞) Ku Chim Sip I Won explains ① the name, the form and the use of nine kinds of neddles, ② and reinforcement and reduction through inserting the neddle in the same direction as the channels runs or in the opposite direction, and closing or enlarging the acupuncture hole etc., ③ and notice and contraindication in applying acupuncture, ④ and the close relationship of between diagnosis and acupuncture, ⑤ and the adverse reaction through a wrong treatment. Thus, it is very important to studying this part which comments Ku Chim Sip I Won. Summerizing the contents of the "So Chim Hae(小鍼解)" in reference to the contents of Ku Chim Sip I Won. the contents were as follows; What attracts our attention in chapter Ⅰ is the basic principles of applying acupuncture. What attracts our attention in chapter Ⅱ is reinforcement and reduction based on shortage and surplus, and their related reactions of human body. What attracts our attention in chapter Ⅲ is dividing the invasion of pathologic factors into three category(upper, medium, lower part) and then its mechanism and therapy, and the adverse effects through wrong treatmant. What attracts our attention in chapter Ⅳ is explaining the importance of observation of complexion and paltation of abdomen. Chim Hae(鍼解) in So Moon(素問) also comments Ku Chim Sip I Won in the same way that this part does, and yet there are not a few differences from this part in noting. Thus we need the comparative study of between this part and Chim Hae to understand Ku Chim Sip I Won. Besides we have to add the comparative study of views of distinguished physicians to correctly understand. I therefore made a comparative study both on the contents of those parts related to this part,and on the commentations of distinguished physicians to correctly understand Ku Chim Sip I Won, the important part about acupuncture.