A medical liquid container consists of a container body (10) of flexible synthetic resin material having a nozzle (12) and a plug portion (30) for closing or blocking the nozzle (12) and integrally formed with the container body (10) through a thin portion formed on a root area of the plug portion (30). A cap member (20) has an engaging hole which is tightly fitted to the plug portion (30) of the container body (10) so as to turn with it and break the thin root area when the cap member (20) is turned to open the container. <IMAGE>
