Pine wood nematode, Bursaphelenchus xylophilus, is a causative organism to induce pine wilt disease in many varieties of pine trees. Until 2006, Monochamus alternatus had been known as the only insect vector of pine wood nematode in Korea which targeted on Pinus densiflora (Japanese red pine) and P. thunbergii (Japanese black pine). However, pine wilt disease was also reported from Korean pine tree (Pinus koraiensis) in 2006 and we found another insect vector, M. saltuarius, was involved to transmit pine wood nematode. Both Monochamus species were confirmed to transfer pine wood nematode to their hosts but, there is no detail information about other transmitted nematode. Especially Bursaphelenchus mucronatus is common species transmitted by Monochamus species which is morphologically closed to B. xylophilus. Moreover B. mucronatus have two genotypes; one is East Asian type and the other is European type. Both genotypes of B. mucronatus were found in Korea but, the host and vector information related to the genotypes of B. mucronatus was not clear. Monochamus saltuarius was collected from three different geographical locations and nematodes were extracted and identified. For the identification of the juveniles, nematode DNA was extracted and ITS-RFLP analysis was done by PCR and gel electrophoresis. The selected enzymes were Hinf I, Alu I, Msp I, Hae III, Rsa I. Most of Bursaphelenchus species carried by M. saltuarius, which collected from pine wilt disease-free area, was determined as European type of B. mucronatus. We will compare the nematode species and genotypes carried by M. alternatus and M. saltuarius. In addition the rate of nematode carrying insect and the average number of nematode per single insect will be counted and compared.