PROBLEM TO BE SOLVED: To provide a mixed injection member to be connected to a blood circuit and capable of sufficiently suppressing disadvantage that a blood clot is formed in its inside.SOLUTION: This mixed injection member 15 is provided with a communication passageway 20 communicated with the upstream section and the downstream section of the blood circuit 1 and allowing the passing of blood, and an insertion section 22 at the inner wall 20a of the communication passageway 20. An insertion tube is inserted into the insertion section 22 to communicate the communication passageway 20 with an insertion tube. The whole circumference of the inner wall 20a of the communication passageway 20 is formed flush with the inner circumferential face of the blood circuit 1 into a continuous face with no level difference.COPYRIGHT: (C)2010,JPO&INPIT【課題】血液回路に接続される混注部材であって、内部に血栓が形成される不都合を十分に抑えることができる混注部材を提供する。【解決手段】血液回路1の上流部および下流部に連通して血液が通過可能な連通路20を備え、該連通路20の内壁20aに挿通部22を設け、該挿通部22に挿通管を挿通して連通路20と挿通管とを連通可能な混注部材15であって、連通路20の内壁20aの全周を血液回路1の内周面と段差のない連続面上で揃う状態に形成した。【選択図】図2