Abstract: The high temperature drying (HTD) method has been widely used in treating softwood and nonrefractory hardwood. However, there is little literature about the application of this method to most of the refractory hardwood, e. g., Fraxinus mand-shurica.A series of HTD experiments has been carried out by the author (with the wet bulb temperature at 97c, and the dry bulb temperature up to 110C) on Fraxinus mandshurica planks of 5 cm thickness and desirable results has been obtained.In the experiments the reactions of planks to various medium conditions, the effect of "fluctuated drying process" and the change of colors of planks in drying runs were observed, and the temperature distributions in planks determined. The time required for planks to dry from the moisture content of 31% to that of 10.6% was 52 hours and from the MC of 42.7% to that of 15.2% was 99 hours.The test results show that as compared with conventional drying method the HTD method can greatly reduce the drying time of thick planks of Fraxinus mandshurica without end check, surface check, honeycomb and twist.Discussions on drying mechanisms are made and a reference drying schedule is suggested.