To provide a liquid medicine storage bag which is good in hygiene due to its easiness for twist-opening operation despite its flexible resin-made container body, requires no separate disposal after use, and also enables easy operations in taking out the liquid medicine, feeding another medicinal agent, and mixing them.

This liquid medicine storage bag is provided with the flexible resin-made container body 1, a flow passage 3a through which a liquid medicine to be contained in the bag passes, and a guide protrusion which is to be cut off before use. The guide protrusion is integrally molded with a resin-made holding part 2 which is attached to the container body by solvent welding in a way that the flow passage communicates the inside of the container body. The guide protrusion, which is also provided with a gripper 4b on its top for rotation operation, is to be cut off when the gripper is twisted off the holding part to open the bag. The holding part is provided with a flange to support the container body when opening the bag.