Abstract: The Lo bud germination inhibition of Tiegun dioscorea opposita thunb occurred, the yam stem water content, total soluble sugar and soluble protein content respectively declined from 70.2039% to 66.61544%, from 72.21325mgg-1 to 25.87888mgg-1 and from 508.5394gg-1 to 258.4231gg-1, and MDA and O2 contents respectively increased from 0.62mmolg-1 to 8.033122mmolg-1 and from 32.99713gg-1 to 35.53642gg-1 after it was irradiated by 2.5mW He-e laser for 30min. After the laser irradiation, the superoxide dismutase (SOD) activity of Tiegun dioscorea opposita thunb increased from 494.864Ug-1 to 1105.85Ug-1 in the initial period of its storage and then declined from 1105.85Ug-1 to 959.167Ug-1.