Abstract: This paper, by using fuzzy recognition theory, calculates and analyzos the basic charactetistics of seismic anomalous μ value before the earthquakes of Ms5.0 in Hebei province and its adjacent areas from Augrst in 1980 to 1992, and presents the recognition index for seismic Precurssors, which has active significance for the study of seismic comprehensive prediction methods in this region.