A CONNECTOR OF THE PRESENT INVENTION COMPRISES AN OUTER TUBE (8) PROVIDED WITH A CONNECTING PORTION AT THE LEADING END THEREOF, THE CONNECTING PORTION (10) BEING OPEN SO THAT A CYLINDRICAL OBJECT TO BE CONNECTED CAN BE INSERTED AND CONNECTED. A HOLLOW TUBULAR BODY (5) THE LEADING END OF WHICH IS OPEN IN THE AXIAL DIRECTION TOWARD THE CONNECTING PORTION (10) AND A CLOSING MEMBER (11) MADE OF AN ELASTIC MATERIAL ARE PROVIDED IN THE OUTER TUBE (8). AN INSERTION HOLE (18) THROUGH WHICH THE TUBULAR BODY (5 ) IS INSERTED WHEN THE CLOSING MEMBER (11) IS RETREATED IS PROVIDED IN THE CLOSING MEMBER (11). THE CONNECTOR IS PROVIDED WITH TIGHTENING MEANS (21) FOR TIGHTENING THE CLOSING MEMBER (11) FROM THE OUTER PERIPHERY SO THAT THE INSERTION HOLE (18) IS CLOSED, AND URGING MEANS (12) FOR URGING THE RETREATED CLOSING MEMBER (11) IN THE ADVANCE DIRECTION WHEN THE TUBULAR BODY (5) PENETRATES THE INSERTION HOLE (18). WHEN A CYLINDRICAL OBJECT TO BE CONNECTED PROVIDED AT THE TIP END OF A SYRINGE, A TUBE, OR THE LIKE IS CONNECTED TO THE CONNECTOR OF THE PRESENT INVENTION, A RELIABLE CONDUCTING STATE OF THE TUBULAR BODY CAN BE FORMED.
