PROBLEM TO BE SOLVED: To provide a connector for extracorporeal circulation circuits suited to a connection with a port in the extracorporeal circulation circuit.SOLUTION: The connector for an extracorporeal circulation circuit for use in a connection to a port 1 with a joint provided in the extracorporeal circulation circuit, includes a port connection part 11 that is connected to the port so as to be fitted to tapered parts 3A and 3B provided on the outer periphery of a joint 2. A diameter-enlarged part 12, the inside diameter D2 of which is enlarged, is formed at the inner periphery of the port connection part 11 so as to produce a step with respect to an inner peripheral surface 13a of an internal flow passage 13 of the connector, while a tapered surface 12b is formed on the inner periphery of the enlarged part 12 so as to be inclined along a slope of the tapered part 3A located at the tip endmost of the joint 2.【課題】体外循環回路内のポートとの接続に適した体外循環回路用のコネクタを提供する。【解決手段】体外循環回路に設けられた継手付きポート１との接続に使用され、継手２の外周に設けられた先細りのテーパ部３Ａ、３Ｂに嵌め合わされるようにしてポート１と接続されるポート接続部１１を備えた体外循環回路用のコネクタにおいて、ポート接続部１１の内周には、コネクタの内部流路１３の内周面１３ａに対し、段差が生じるようにして内径Ｄ２が拡大された拡大部１２を設け、拡大部１２の内周には、継手２の最先端に位置するテーパ部３Ａの斜面に沿って傾斜する先広がりのテーパ面１２ｂを形成する。【選択図】図１
