We had evaluated of insecticidal effect from Insecticide-treated net (ITN) that coated by deltamethrin against Monochamus alternatus which serves as a vector for Bursaphelenchus xylophilus. In this experiment, vector has been shown that rapid insecticidal effect response time within 1 hour when they were contacted with ITN. In addition, vectors were showed high mortality within 48 hours. To evaluate insecticidal persistency of ITN and whether releasing insecticide to water, ITNs were soaked in water over various time periods. Water has not shown insecticidal effect to vectors and small amount of insecticide were detected that would not be harmful to other non-target organic being such as honeybee. Also, reduction of insecticidal effect was not observed from the ITN. Taken together, our results suggest that ITN had got highly insecticidal effect to vector as well as could be applied to effectively prevent dispersal of the vector on the field.