Abstract: This paper discusses the relation detween δHe/Ar ratio variation of Tayuan fault gas and several earthuakes from June/1990 to December 1991.From several obtained earthquake examples, it can be seen that,for some earthquakes,the δHe/Ar ratio shows a negative anomaly,but for other earthquakes, showing a positive anomaly.The δHe/Ar ratio has a better capability to reflect earthquakes.