Abstract: Studies on selecting Monochamus alternatus attractant were made from 1998 to 1999.The results showed that the attract ability of the attra tant M99-1 to the pine sawyer adult is the strongest.Main componentes of the attractant M99-1 were terpent,acetaldehyde and acetone.Each trap can catch 151.5 pine sawyers in average,and the amount of egg declined by 1204.4.It is concluded that this attractant played an important role in monitoring the population density of M.alternatus,the amount of adult carring Bursaphelenchus xylophilus and controling the pine sawyer.