Medicate the patient with right dose and time has significant meaning to the efficiency of treatment as well as the control of the signs and symptoms of the disease. Therefore, nurses and other medical professionals become more concern about reminding, controlling and supervising the medication administration of the patients especially with the chronic disease and the elderly. The objective of this study was to design a microcomputer controlled multi-dosing device for the chronic patient. The multi-dosing device was built with the combination of CPU 8751, LED, LCD, crystal, buzzer, micro-switch etc. The software for this device, was written in assembly language, compilied and then was written into the EPROM of 8751 to drive the hardware of this system. It showed a satisfactory design in the function of programming and good stability in the in vitro testing.