通过研究安徽省五河井水位、沪江井井压和流量的观测资料 ,笔者发现了大震前远场中期异常的证据。菲律宾 8.0级地震 ( 1 990年 7月 1 6日 )前 ,五河井 (Δ =2 0 33km)水位的 M2 波的振幅比α和相位差 Δθ ,均有近 1 7个月的低值异常 ;庐江井 (Δ =1 80 0 km)井压和流量均存在近 36个月的低值异常。台湾海峡 7.3级地震 ( 1 994年 9月 1 6日 )前 ,五河井 (Δ =1 1 2 1 km)水位 M2 波α和 Δθ以及庐江井 (Δ =930 km)井压和流量分别有 35～ 36个月低值异常。地震发生时 ,上述低值异常均出现显著的恢复和回跳、同震异常变化。震后 ,所有异常保持高值和正常年变化。从 1 986年 1 2月至 1 997年 6月 ,二井观测资料仅在二次大震前出现同态、同步、同震的异常变化。事实表明 ,某些强震可能存在远场中期前兆异常 By studying the water level of Wuhe Well in Anhui Province and the well pressure and flow in Shanghai Well, the author found evidence of mid-term anomalies in the far field before the earthquake. Before the MS 8.0 MS 8.0 (July 1, 1990), there was a low value anomalies of nearly 1.7 months for the M2 wave amplitude ratio α and the phase difference Δθ in the Wuhe well (Δ = 2033km) There are nearly 36-month low anomalies in well pressure and flow in Lujiang well (Δ = 180,000 km). Before the MS 7.3 Taiwan Strait earthquake (September 1, 1994, September 1994), the well pressure and flow rates of the M2 waves α and Δθ in the Wuhe well (Δ = 11 122 km) and the Lujiang well (Δ = 930 km) were 35 ~ 36 months low abnormalities. At the time of the earthquake, all the above low anomalies showed significant recovery and rebound, and the coseismic anomalies changed. After the earthquake, all anomalies remained high and normal year changes. From January 1986 to June 1997, the observed data of No.2 well presented the abnormal changes of homomorphism, synchronicity and coseismicity just before the second major earthquake. The fact shows that some strong earthquakes may have a far-field medium-term precursor anomaly