Fired-logs suffered seriously from insects and fungi had got a good protection by fumigation with sulphuryl fluoride （SO,2,F,2,） and spraying with emulsion of Lindane and "6781" wood preservative during July to September in 1988 at Changying Log Yard, Amur Bureau of Forestry, Daxinganling, Heilongjiang province. The retention was 70 grams/m,3, for fumigant of sulphuryl fluoride, 0.10—0315 kg/m,3, for Lindane and 0.70kg/m,3, for "6781" wood preservative. The mortality of the larvae of longhorn beetles Was 100% for the fumigant and over 95% for Lindane, "6781" wood preservative had an obvious effect on mould and blue stain.