Abstract: This paper has studied the characteristics of several anomalous waveforms recorded at Jingtai seismic station and their distribution characteristics with time. The quantitative anal sis is made for the quantity, type and amplitude of the anomalous waveforms appeared in different stages by seismomitry method and statistical method. It is found that before the Jingtai M6.2 earthquake on October 20, 1990, the anomalous waveforms showed quite-dence-quite-dence phenominon; immediately before the earthquake, the quantity of various anomalous waveforms increased, the amplitude enlarged, the duration of anomalies elongated; after the earthquake the anomalous waveforms disappeared very soon. Compared with other precursors, it can be considered that the apperance of anomalous waveforms may be related with the development of the Jingtai earthquake. According to the variational characteristics of such type waveform, it may be possible to predict earthquakes.