PURPOSE: To prevent an erroneous input and to improve the work efficiency by utilizing information registered in advance, and expanding it automatically by the system.

CONSTITUTION: The system is provided with a display and input device 1 for data, a data processor 2, an output device 3 for printing the medical treatment contents, a file 4 for keeping a pattern of a medical treatment plan, a file 5 for keeping a modified medical treatment plan, and a file 6 for keeping a patient's state for modifying the content of the medical treatment plan. In such a state, a doctor inputs medical treatment data from the device 1, and stores it in the device 4. Also, in accordance with the contents of its medical treatment data, the data processor 2 reads out necessary data from the files 4-6, edits them, and thereafter, outputs them to the display and input device 1 and the output device 3. Therefore, medical treatment information required for a patient can be transferred to each post. That is, the medical treatment plan converted into a pattern is modified and expanded automatically in accordance with a patient's state, and the content of the medical treatment can be transferred automatically to the related post, based on a date.