Abstract: Experiments were conducted on different duration of steam explosion of branch fragments of Cinnamomum bodinieri for its water extract. Analysis were made on pictures of scanning electron microscope, as well as on lignin, cellulose, carbon content and organic nitrogen content of different treated fragments and control (no explosion).Water extract from different treated fragmentes was added to the liquid culture media for studying the total triterpene and total polysaccharide content of mycelium in liquid culturing.The results show that the form of the fragmentes changed obviously after steam explosion.Scanning electron microscope showed that larger fragments fractured and gradually had many small holes.The contents of cellulose, lignin, carbon and nitrogen increased slowly with longer duration of explosion.But carbon-nitrogen ratio decreased significantly even to the ideal level for fungus culture medium at 300 s.The experiment resulted that steam explosion could promote the mycelium of total triterpenes and total polysaccharide production, the highest had 16.80% and 25.00% more than the control.