The present invention provides a liquid specimen analysis disk assembly, which prevents a liquid specimen from adhering onto a surface of a disk and leaking out of the disk, and is easy to handle during injection of the specimen. The disk assembly includes a guide member detachably provided on the disk and having a guide hole for guiding a distal portion of a specimen injector toward a specimen injection port, so that the specimen is injected into a specimen spreading cavity or an internal channel from the specimen injection port and rotated about an axis of the disk, and the specimen spread in the channel following the rotation is optically scanned for analyzing. The distal portion of the specimen injector is inserted into the guide hole and assuredly guided to the center of the specimen injection port, thus preventing the specimen from adhering onto the disk surface around the injection port.