Provided a port member for an infusion solution bag that is capable of suppressing occurrence of gaps or wrinkles in a sealed portion in a manufacturing process, and preventing damages to resin sheets of a bag body during storage or transportation. A port member for an infusion solution bag includes a tubular body portion having one end sealed by a plug member structured to enable a hollow needle to be pierced into the plug member, and a tubular to-be-sealed portion continuously formed with an other end of the body portion and having an inner space communicated with the inside of the body portion, the to-be-sealed portion being held between and sealed to end portions of resin sheets overlapped together to form a bag body having an inner space for accommodation of at least a medicine, in which the to-be-sealed portion thus sealed has a radially flattened shape.
