【Background】Studying the new fumigant, ethyl formate against Bursaphelenchus xylophilus can be useful in the advent of methyl bromide being phased out. 【Method】The toxicity and concentration-time product of ethyl formate were tested indoor against nematode isolated from pine wood. 【Result】The LC50 of B.xylophilus to ethyl formate in 3, 6, 12, 24 and 48 h at 25 ℃ were 2.63, 1.60, 0.99, 0.41 and 0.20 mg·L-1, respectively. The toxicity of ethyl formate was significantly affected by temperature, with B.xylophilus mortality decreasing from 63% at 19 ℃ to 100% at 29 ℃ for a concentration of 1.85 mg·L-1 ethyl formate treatment. The ethyl formate fumigation could completely kill nematodes with 12 hours exposure time.The LCt99 of ethyl formate for B.xylophilus were 453.94 mg·h-1·L-1 after 6 h exposure and 424.14 mg·h-1·L-1 after 12 h exposure. 【Conclusion and significance】The results confirm that ethyl formate could be used as a fumigant against B.xylophilus.