Anomaly characteristics of earth-resistivity,hydrochemistry,underground water behaviors,ground stress and deformation during the Yongdeng M_S5.8 earthquake in Gansu Province on Jul. 22, 1995 were studied, and so the following conclusions were obtained:① The spatial distribution of medium-short (one year time scale) and short-imminent anomalies accords with the special relation of ‘anomaly-focal site-causitive mechanism active-master fault’ put forth by authors, and the medium period anomaly which lasted about 2-3 years is concentratedly distributed along the NW fault zone on north margin of west Qinling mountain and Haiyuan-Tongwei-Wudu fault zone. ② The additional compression stress field in the NNW-SSE direction come into being during one year before the earthquake, which caused the displacement of the focal fault. ③ The focal precursors are concentratedly distributed around the focal area, while the field precursors occur along the two active master faults mentioned above. Most of anomalies belong to the focal precursors, while a few anomalies are the field precursors. As far as duration time of anomalies,the field precursors appeared more precedently than the focal precursors.