Abstract: This paper described the hydrog eolo gical characteristics of the mo ni tored spring si tes, the origin and existent form of their sulfides. Combined the earthquakes cased in the past more than 20 years, the earthquake-ref lecting fea tures are analyzed and summarized. The results indica te that the ear thqua ke precursor anomaly of the sulfides is usually no rmal, which show sacertain repeated pro perty. That is, the change of sulfide values isas follows: backg round value-trend ri se(or sudden ri se)-t rend drop (or sudden drop)-recov ered to the backg round value. Usually the earthquakes occurred in the stag e w hen sulfide values changed from the hig hervalue to the lowvalue(close to the backg roundone). In this paper, the autho rsalso di scussed the origin of anomaly and concluded that the evident ef fect of pore pressure(pressure intensity) on thegenera tion of sulfides is the majororigin of sulfides having acertain earthquake ref lecting features.

Key words: Sulfide, Earthquake-reflecting mechanism, Earthquake precursor, Xinjiang Uygur Autonomous Region