Abstract: Based on investigating and analyzing existing equipments and processing technology of red ginseng drying, a set of microcomputer control system was established, in which the temperature and the humidity can be controlled automatically by the APPLE-Ⅱ microcomputer, to improve quality of red ginseng in processing and reduce energy loss and production cost. The results of experiments and production show that the system is stable and practical. It can control variation in temperature of ± 5℃, humidity of 2 %～3 % and each drying room can be controlled by the center computer. The operation of the system is easy, saves time and labour, and good quality of dried red ginseng can be obtained. This system is suitable to the drying of other similar goods too.