According to UNESCO (1973) classification, modified by Phan Ke Loc (1985), current forest vegetation of Song Ma district, Son La province includes 4 formation classes with 13 formations. Among them, the closed forest formation class includes 4 formations, the woodland (open stands of trees) formation class includes 1 formation, the scrub (shrubland or thicket) formation class includes 2 formations, the herbaceous vegetation formation class includes 6 formations.