Abstract: Oak(Cyclobalanopsis spp.)is widely distributed in Yunnan province of China,and it is also an excellent raw material for decoration and highgrade furniture.But up to now,it is not widely used because it is hard to be dried.Steaming of lumber has been proposed as an aid in drying for decades.In this paper,the effects of amorphous steaming on the shrinkage coefficient,air permeability and initial moisture content(MC) of oak were investigated.The air permeability of wood sample was measured by rising water displacement method.The results show that five hours of steaming caused a drop of approximately 5% in initial MC,a increase of about twice in longitudinal air permeability,a minor increased shrinkage coefficient,but the effects of steaming on transverse air permeability were not significant,when compared to unsteamed oak samples.