Abstract: This article studies the changes of the main chemical composition of the chinese drugs Gastradia Elata BL and Angelica Sinensis (Oilv) which were irradiated by ~(60)Co-γray and stored for half an year. The content of the main chemical composition gastrodin of Gastradia Elata BL was measured by thin-layer chromatography and gas chromatography and the main chemical composition Ligustilide of the essential oils of Chinese Angelica was also measured. The result shows that the contents of the main chemical composition gastrodin of irradiation groups and control groups are almost the same. The content of the main chemical composition Ligustilide of the irradiated Chinese Angelica is close to the content of the control (not irradiated). There is no remarkable difference after the data were treated statistically (P>0.05). The thin-layer chromatography colour-maculates were almost the same with the same R_f exponent. Irradiation of the tuber of elevated gastrodia and Chinese Angelica with 6×10~3 Gy of ~(60)Co γ-rays and with subsequent storage of half an year will not change the effective composition of the drugs.