Abstract: It was showed by the survey that there were 12 species harmful to forestry in Nujiang Prefecture, Yunnan Province. The 12 pest species included Ageratina adenophora, Chromolaena odorata, Achatina fulica, Lawana imitata, Monochamus alternatus, Tomicus piniperda,Dendrolimus houi, Lymantria monacha, Dryocosmus kuriphilus, Eriosoma lanigerum, Mycosphaerella aleuritidis and Pinusarmandii coleosporium etc.. The distribution, the host species, as well as the harmfulness of these pest species to forestry production were analyzed.