Abstract: The cryopreservation of Bursaphelenchus xylophilus was investigated. The effects of different cryoprotectants (1 %-5 % DMSO, 5 %-25 % glycerol) on cryopreservation of nematodes and the fertility and infectivity of cryonematodes were evaluated. The results indicated that the survival rate of B. xylophilus was up to (39.4±6.6) % or (375±21.8) % after storage for 1 day at －80 ℃ by using 15 % glycerin or 4 % DMSO respectively as cryoprotectant. And it didnt decline significantly after storage for 10 days or a month. When cryopreserved nematodes were plated onto Botrytis cinerea, they reproduced rapidly. Cryopreserved nematodes were as pathogenic as untreated nematodes to Japanese black pines.