PROBLEM TO BE SOLVED: To provide a pump connector allowing a diameter expanded part formed in a communication flow path to be attached adjacent to a squeezing part of a squeezing pump and that can suppress bubble retention.SOLUTION: A pump connector 9 comprises a main tube connection part 9a connectable to a main tube 1, a squeezed tube connection part 9b connectable to a squeezed tube 8 that allows a flow of liquid held inside by being squeezed in a longitudinal direction while being compressed in a radial direction by a squeezing part 4b of a blood pump 4, a communication flow path 9c to allow communication between a flow path of the main tube 1 and a flow path of the squeezed tube 8, and a diameter expanded part 9d formed in a prescribed portion of the communication flow path 9c and has a diameter expanded in a tapered manner from an inner diameter dimension of the main tube 1 to an inner diameter dimension of the squeezed tube 8. A gripped part 9g that can be gripped by a grip part 4c formed in a main body 4a of the blood pump 4 is formed in an outer periphery surface of the pump connector 9.
