By interviewing, samples analysis and plants classification, the research has obtained the following results: there are 67 plant species belonging to 37 families, 29 ordoes of 3 sectors (Lycopodiophyta, Polypodiophyta and Angiospermatophyta) which are used as medicines; there are 10 groups of diseases and 23 prescriptions are often used by the San Diu in Phu Luong - Thai Nguyen to treat a number of common diseases.