The pine wood disease caused by the pine wood nematode[Bursaphelenchus xylophilus (Stei- ner &. Buhrer) Nickle]is not only one of the most devastating disease of trees,but an important quar- antined forest disease. It is very important for the methods of diagnosis and quarantine of the pine wood disease to prevent the disease. The research progreses in diagnosis of the disease were reviewed in this paper. It is involved with morphlogic, biochemical and molecular biology identification of the pine wood nematode,prime diagnosis of trees and quarantine of wood infected by B. xylophilus.