There is provided a medicinal liquid injection port to be implanted subcutaneously. A housing main body is provided with a medicinal liquid storage portion therein, an opening portion that opens the medicinal liquid storage portion, and a discharge hole that communicates with the medicinal liquid storage portion and configured to be connected with a tube. A septum attached to the opening portion of the housing main body and provided with a puncturable region that can be punctured with a puncture needle. A contrast portion is disposed in the septum over a thickness direction of the septum so as to detect the puncturable region of the septum with the ultrasonic wave. The contrast portion is provided in the septum within a thickness region of the septum and all of the contrast portion is positioned at an inner side of the septum in the thickness direction of the septum.