The present invention provides an automatic blood-sampling tube preparation device which can detect the presence of the proper or improper blood-sampling tube by selectively taking out a blood-sampling tube and transferring the blood-sampling tube to a label pasting position, printing information of the patient on a label, pasting the printed label on the blood-sampling tube positioned in the label pasting position, and collecting the label pasted blood-sampling tubes in the container for each patient. The device also includes photographing means for photographing an appearance of the blood-sampling tube taken out from the blood-sampling tube containing section and a control means arranged to have a threshold with respect to at least one characteristic information previously extracted from an appearance of a blood-sampling tube, to extract the characteristic information from the appearance image photographed to judge whether the blood-sampling tube corresponds to the instruction information from the doctor.